Summarize the following court judgment. ON: Civil Appeal No. 149 of 1981. From the Judgment and Order dated 6.11. 1980 of the Punjab and Haryana High Court in C.P.A. No. 811 of 1980. M.K. Ramamurthy	 U.R. Lalit	 Shanti Bhushan	 M.R. Sharma	 P.P. Rao	 S.K. Mehta	 B.R. Agarwala	 N.D. Garg	 E.M.S. Anam	 P.P. Sharma	 K.S. Tiwari	 C.V. Subba Rao	 I.S. Goel	 P.H. Parekh	 Sohail Dutt	 Uma Datta and V.P. Goel for the appear ing parties. The Judgment of the Court was delivered by SEN	 J. In this appeal by special leave	 the short question involved is whether respondents Nos. 1 and 2 were entitled to the benefits of the period of service rendered by them as Temporary Engineers on an ad hoc basis in the Irrigation Branch of the Public Works Department	 State of Haryana i.e. prior to their appointment as Assistant Engi neers on regular basis on April 21	 1975 along with the six appellants and respondents Nos. 5 24 for purposes of reckon ing their eligibility for promotion to the post of Executive Engineer under r.6(b) read with the Explanation thereto of the Haryana Service of Engineers	 Class I	 Public Works Department (Irrigation Branch) Rules	 1964	 as amended in 1975	 ( 'Class I Rules ' for short) as also for purposes of their seniority in the cadre of Assistant Engineers. Facts bearing on the question are as follows. In re sponse to an advertisement published in the Daily Tribune of February 6	 1970 inviting applications for appointment as Temporary Engineers on an ad hoc basis	 respondent No. 1 B.S. Jain was appointed as a Tem 609 porary Engineer (ad hoc) w.e.f. January 2	 1971 for a period of six months i.e. after the coming into force of the Har yana Service of Engineers	 Class II	 Public Works Department (Irrigation Branch) Rules	 1964 ( 'Class II Rules ' for short). Prior to this	 respondents No. 2 S.L. Gupta was also appointed as a Temporary Engineer on an ad hoc basis w.e.f. May 19	 1969 by calling his name through the Employment Exchange i.e. subsequent to the coming into force of the Class II Rules. Their appointments were de hors the rules to meet the exigencies of service. In the letters of appoint ment issued to them	 it was specified that their appointment was purely on an ad hoc basis for a period of six months from the date of their joining the post on a fixed salary of Rs.400 plus allowances and their services were terminable without notice. They were specifically informed that the appointment would not entitle them to any seniority or other benefit under the service rules for the time being in force and would also not count towards increment in their salary. They were also intimated that the posts of Temporary Engi neers in Class II service would be advertised in due course by the Haryana Public Service Commission and they should apply for such posts through the Commission	 and that if they were not selected by the Commission	 their services would be liable to be terminated without notice. Also that their inter se seniority among the Temporary Engineers would be in the order of merit in the list of candidates as set tled by the Commission. The services of respondents Nos. 1 and 2 were however continued by the State Government from time to time	 six months at a time	 till the Secretary	 Haryana Public Service Commission by his letter dated July 8	 1973 addressed to the Commissioner and Secretary to the State Government of Haryana	 Public Works Department (Irri gation Branch) conveyed the approval of the Commission to the ad hoc appointment of 251 Temporary Engineers beyond the period of six months till regular appointments were made to the posts through the Commission. Accordingly	 both these respondents continued to hold the posts of Temporary Engi neers on ad hoc basis till the end of the year 1974 i.e. till they were recruited as Assistant Engineers through the Public Service Commission on April 21	 1975 on regular basis. It appears that in response to an advertisement issued by the Public Service Commission in October 1973	 respond ents Nos. 1 & 2 appeared at a competitive examination along with the appellants and respondents Nos. 5 24 and were selected by the Public Service Commission for appointment as Assistant Engineers under the Haryana Service of Engineers	 Class II	 Public Works Department (Irrigation Branch) Rules	 1970. In the letter of appointment issued by 610 the Commissioner and Secretary to Government of Haryana (Irrigation & Power Department) dated January 13	 1975 it was specified that inter se seniority of Assistant Engineers would be determined on the basis of the combined merit list prepared by the Public Service Commission: In the combined merit list prepared by the Commission	 respondents Nos. 1 & 2 were placed very much below the appellants and respondents Nos. 5 24 being at serial Nos. 148 and 150 respectively. It may be stated that the merit list prepared by the Commission has never been questioned before us. A few more facts. The State Government of Haryana by order dated December 20	 1978 promoted 62 Assistant Engi neers including the appellants and respondents Nos. 5 24 as Executive Engineers on a purely ad hoc basis for a period of six months subject to certain terms and conditions. namely: (i) The promotions were subject to the approval of the Public Service Commission as also to the claims of other officers. (ii) Such promotions were not to give any right to the officers for being appointed on a substantive basis as Executive Engineers. And (iii) Such of the officers as had not passed the departmental professional and revenue exami nations were required to pass such examinations within a period of one year or otherwise they were liable to be reverted to their original post. These ad hoc promotions of the appellants and respondents Nos. 5 24 were made in relax ation of the provisions contained in rr.6(b) and 15 of the Haryana Service of Engineers	 Class I	 Public Works Depart ment (Irrigation Branch) Rules	 1964. Presumably	 the State Government excluded from consideration the case of respond ents Nos. 1 & 2 for promotion because in the combined sen iority list they ranked below the appellants and respondents Nos. 5 24 being placed at serial Nos. 148 and 150 respec tively. The ad hoc promotion of appellants and respondents Nos. 5 24 was assailed by respondents Nos. 1 & 2 by a petition under article 226 of the Constitution filed before the Punjab & Haryana High Court mainly on the ground that when qualified persons like them i.e. respondents Nos. 1 & 2 were eligible for being considered for promotion to the post of Executive Engineer under r. 6(b)	 there was no justification whatever for the State Government to grant general relaxation under the proviso thereof to make the ineligible persons eligible for promotion in denial of their claims. It was further pleaded that the State Government having relaxed the condi tion of eligibility under the proviso to r.6(b) read with the Explanation thereof as regards eight years service in the case of promotion of the appellants and respon 611 dents Nos. 5 24 as Executive Engineer on an ad hoc basis	 failed to appreciate that respondents Nos. 1 & 2 who were recruited along with them and had also put in more or less 31/2 years service as Assistant Engineers became entitled to the benefit of such relaxation and the action of the State Government in not considering their cases for such promotion was wholly arbitrary and was tantamount to denial of equal opportunity in the matter of employment in violation of articles 14 and 16(1) of the Constitution. It was also pleaded that the power conferred on the State Government to grant relaxation under r.22 was not a general power but a power to mitigate hardship in a particular case and thus the general relaxation granted by the State Government to some of the respondents who had not passed their departmental profes sional and revenue examinations was invalid. It was asserted that the State Government and the Engineer in Chief	 Irriga tion Department	 Haryana had wrongly treated respondents Nos. 1 & 2 as ineligible for promotion on the ground that the period from January 1971 and May 1969 upto April 21	 1975 i.e. the period during which respondents Nos. 1 & 2 remained employed as Temporary Engineers on ad hoc basis	 could not be treated as period in that class of service within the meaning of r.6(b) i.e. in Class II service. The specific stand taken by the State Government in the return filed before the High Court was that respondents Nos. 1 & 2 were recruited to the post of Assistant Engineer on April 21	 1975 and thus had only about 31/2 years service on December 20	 1978 to their credit when appellants and re spondents Nos. 5 24 were promoted as Executive Engineers on an ad hoc basis. Prior to their appointment as Assistant Engineers	 respondents Nos. 1 & 2 had been appointed as Temporary Engineers on ad hoc basis de hors the rules and under the terms of appointment they were not entitled to any seniority or other benefit under the service rules as a result of such appointment. Further	 it was pleaded that respondents Nos. 1 & 2 in the seniority list prepared by the Public Service Commission were ranked junior to the appel lants and respondents Nos. 5 24 and therefore they were not entitled to be considered for promotion. A learned Single Judge (R.N. Mittal	 J.) by his judgment dated October 8	 1980 quashed the impugned order of the State Government making ad hoc promotions of the appellants and respondents Nos. 5 24 and directed the State Government to reach a decision afresh as regards the ad hoc promotions with advertence to the observations made by him. In his judgment the learned Single Judge repelled the contention of respondents Nos. 5 24 for being considered for promo 612 tion since none of them had completed eight years ' service as Assistant Engineer on the ground that the State Govern ment was empowered in terms of proviso to r. 6(b) to relax generally	 in public interest	 the condition regarding eight years ' experience for reasons to be recorded in writing. He found on perusal of the records placed before him that reasons for the relaxation in public interest of the condi tion of eight years ' service imposed by r.6(b) had in fact been recorded for reducing the period to 31/2 years in consultation with the Finance Department. He accordingly held that the ad hoc promotion of the appellants and re spondents Nos. 5 24 was not invalid on that account. The learned Single Judge however accepted the contention of respondents Nos. 1 & 2 that they were entitled to the bene fit of the period of continuous officiation as Temporary Engineers on an ad hoc basis from January 1971 and May 1969 to April 21	 1975 in reckoning eight years ' experience in that class of service within the meaning of r.6(b) i.e. Class II service by reason of Explanation to r. 6(b) and were therefore eligible for promotion to the post of Execu tive Engineer under r. 8(2) in view of the definition of the expression 'Temporary Engineer ' contained in r.2(5)	 as amended in 1975. He also upheld their contention that the power conferred on the State Government under r.22 was not a general power of relaxation but a power exercisable only to mitigate any undue hardship in the case of a particular individual and therefore the impugned order of the State Government permitting relaxation in the case of respondents Nos. 9	 10 and 11 Gyan Singh	 P.D. Kadian and C.P. Goel as regards the passing of the departmental professional and revenue examinations as required by r. 15 was invalid. Upon that view	 the learned Single Judge allowed the Writ Peti tion and quashed the impugned order of the State Government for the ad hoc promotion of the appellants and respondents Nos. 5 24 as Executive Engineers. Incidentally	 the judgment of the learned Single Judge leaves untouched the impugned order insofar as it relates to the ad hoc promotion of 37 Assistant Engineers to the post of Executive Engineer. Thereupon	 the appellants preferred an appeal under cl. 10 of the letters patent but the appeal was dismissed in limine by a Division Bench (P.C. Jain & C.S. Tiwana	 JJ) by its order dated November 6	 1980. The learned Judges stated that they were in full agreement with the view expressed by the learned Single Judge. The appellants apparently advanced a contention that the appointment of respondents Nos. 1 & 2 as Temporary Engineers on an ad hoc basis was contrary to Para 8.312 of the Manual of Administration and therefore the period during which they worked as Temporary Engineers (ad hoc) could not 613 be taken into consideration. The learned Judges repelled the contention on the ground that no such point was taken before the learned Single Judge. We must at the very outset observe that the judgment of the learned Single Judge quashing the impugned order of the State Government for the promotion of the appellants and respondents Nos. 5 24 as Executive Engineers on an ad hoc basis on the ground that the State Government could not have relaxed the condition of passing the departmental profes sional and revenue examinations prescribed under r. 15 of the Class I Rules by taking recourse to r. 22 which did not confer a general power of relaxation can hardly be sus tained. We are afraid	 the learned Single Judge was com pletely misled in taking the view that he did. This was not a case of relaxation at all but a question of prescribing the period during which such examination had to be cleared as required under r. 15. R. 15 in terms provides that the departmental professional and revenue examinations for purposes of promotion to the Class I service have to be passed within such period as may be prescribed. The word 'prescribed ' in r. 15 clearly empowers the State Government to provide for the period during which the promoted officers had to pass the departmental test. In terms of that rule	 the State Government by the impugned order directed that the officers who had not passed the departmental professional and revenue examinations were required to pass such examina tions within a period of one year otherwise they were liable to be reverted to their original post. It must be said in all fairness that learned counsel for respondents Nos. 1 & 2 did not support this part of the Judgment. After having heard learned counselor the parties quite at some length in a heating lasting over several days	 we feel that irrespective c f the merits of the contentions advanced	 no useful purpose would be served in maintaining the judgment of the High Court insofar as it quashes the impugned order of the State Government dated December 20	 1978 for the promotion of the appellants and respondents Nos. 5 24 as Executive Engineers on an ad hoc basis after a lapse of such a long time as it would create unnecessary administrative complications. During the heating we ex pressed our doubts about the wisdom of the High Court in entertaining the Writ Petition of respondents Nos. 1 & 2 particularly when the impugned order of the State Government making promotion of the 62 Assistant Engineers including the appellants and respondents Nos. 5 24 as Executive Engineers was purely on an ad hoc basis for a period of six months and expressly made subject to the fights of other officers. Instead of interfering with the impugned 614 order of the State Government the proper course for the High Court should have been to issue a direction to the State Government to consider the cases of the eligible officers including respondents Nos. 1 & 2 for ad hoc promotion as Executive Engineers if their turn was due for such promotion according to their placement in the seniority list and it should have in the meanwhile allowed the appellants and respondents Nos. 5 24 to continue in their posts as Execu tive Engineers (ad hoc) subject to the condition that while considering their cases for promotion the State Government would not take that circumstance into consideration that they had continued to function as Executive Engineers on an ad hoc basis. That course commends to us for another reason as well. Although the High Court by its judgment and order dated October 8	 1980 quashed the impugned order of the State Government dated December 20	 1978 making the ad hoc promo tions and issued a direction that the Government should reach a decision afresh in the matter	 the fact remains that neither the judgment of the High Court nor the directions made by it have taken effect. On the contrary	 this Court while granting special leave on January 14	 1981 stayed the operation of the judgment of the High Court. As a conse quence	 the result has been that the appellants and respond ents Nos. 5 24 have continued to function as Executive Engineers on an ad hoc basis for the last about eight years under the interim order of stay. Incidentally	 the judgment of the High Court leaves untouched the promotion of 37 Assistant Engineers and Executive Engineers. The State Government will also have to give effect to the decision of this Court in A.S. Parmar 's vs State of Haryana	 [1984] 2 SCR 476 laying down that a degree in Engineering was 'not an essential qualification for promotion of Assistant Engineers in the Irrigation Branch to the cadre of Executive Engineers in Class I service under r.6(b) of the Class I Rules and therefore the Assistant Engineers who are diploma holders are equally eligible for such promotion. The State Govern ment in the Public Works Department (Irrigation Branch) by a notification dated June 22	 1984 purported to effect an amendment to r.6(b) of the Class I Rules with a view to nullify the decision of this Court in A.S. Parmar 's case. By a separate judgment in the connected Writ Petitions Nos. 630 32/84 delivered today	 we have struck down the impugned notification as offending against articles 14 and 16(1) of the Constitution and also as ultra vires the State Government by reason of the proviso to s.82(6) of the Punjab Reorganisa tion Act	 1966. It appears that the State Government has been treating a degree in Engineering referred to in Cl.(a) r.6 as an essential qualification for promotion to the post of 615 Executive Engineer in Class I service in the case of offi cers in Class II service presumably on the view expressed by the Punjab & Haryana High Court in O.P. Bhatia vs State of Haryana	 ILR The controversy was settled by the decision of this Court in A.S. Parmar 's case and it overruled the decision of the High Court in O.P. Bhatia 's case and held on a consideration of the relevant rules that the qualification of degree in Engineering was not necessary in the case of officers in Class II service for promotion to the post of Executive Engineer. That apart	 we must deal with the appeal on merits as the judgment of the High Court leaves much to be desired. Issues raised in this appeal by special leave are of far reaching significance to the civil services. It involves a claim by persons who had been in employment in the Govern ment service on a purely ad hoc basis de hors the rules	 that they were entitled upon their absorption to the post on a regular basis	 to the benefit of the period of their continuous officiation as temporary employees on ad hoc basis for determining their eligibility for promotion to the higher grade or post. The questions presented are whether the principles laid down in N.K. Chauhan & Ors. vs State of Gujarat & Ors. 	 ; and S.B. Patwardhan & Ors. vs State of Maharashtra & Ors. 	 ; reiterated in Baleshwar Das & Ors. vs State of Uttar Pradesh & Ors. 	 [1981] 1 SCR 449 and subsequently followed in several deci sions	 that ordinarily in the absence of any specific rule of seniority governing the cadre or service	 the length of continuous officiation should be counted in reckoning sen iority as between direct recruits and promotees	 should also be extended in determining seniority of such adhoc employees vis a vis direct recruits	 and whether the failure on the part of the Government to count the entire period of offici ation as such ad hoc employees would be per se arbitrary and irrational and thus violative of articles 14 and 16(1) of the Constitution inasmuch as the temporary service in the post in question was not for a short period intended to meet some emergent or unforeseen circumstances	 but to meet the exi gencies of the service. It is asserted that the recent pronouncement of this Court in the case of Narendra Chadha & Ors. vs Union of India & Ors. 	 ; supports this view. The argument at first blush appears to be plausi ble but on deeper consideration is not worthy of acceptance. We proceed to give reasons therefor. We are not aware of any principle or rule which lays down that the length of continuous officiation/service is the only relevant criterion in determining seniority in a particular cadre or grade	 irrespective of any specific rule of seniority to the contrary. It is necessary to 616 emphasise that the principles laid down in the two leading cases of N.K. Chauhan and S.B. Patwardhan	 reiterated in Baleshwar Das 's case and subsequently followed in several decisions are not an authority for any such proposition. These decisions particularly that in Baleswar Das 's case clearly lay down that ordinarily and in the absence of any specific rule of seniority governing the cadre or service	 the length of continuous officiation should be counted in reckoning seniority as between direct recruits and promo tees. These authorities nowhere lay down that the same principle i.e. the length of continuous officiation must be the sole guiding factor and the only criterion in determin ing seniority of such ad hoc employees vis a vis direct recruits. The contention on behalf of the appellants firstly is that the High Court was dearly in error in holding that the entire period of service of respondents Nos. 1 & 2 as Tempo rary Engineers on ad hoc basis i.e. the period from January 1971 and May 1969 to April 21	 1975 had to be counted not only for purposes of their seniority under r.8(2) of the Class I Rules but also for the purpose of their eligibility for promotion to the post of Executive Engineers under r.6(b). It is said that the High Court failed to appreciate that respondents Nos. 1 & 2 were not recruited as Temporary Engineers under the instructions contained in the Manual of Administration issued under the Punjab Service of Engineers	 Class II	 Public Works Department	 (Irrigation Branch) Rules	 1941 or under the Punjab Service of Engineers	 Class II	 Public Works Department (Irrigation Branch) Rules	 1970	 but their appointment as Temporary Engineers was purely on an ad hoc basis de hors the rules and therefore they did not fail within the ambit of the definition of the expression 'Class II Service ' as defined in r. 2(5)	 as amended in 1975. Secondly	 the High Court failed to take into account the fact that respondents Nos. 1 & 2 became members of Class II service only on April 21	 1975 when they were recruited as Assistant Engineers on a regular basis through the Public Service Commission. Till then they did not answer the de scription of 'Temporary Engineers ' as defined in r.2(5). They did not even figure in the notification dated May 18	 1982 issued by the State Government under r.3 constituting the service of Engineers as Class II service w.e.f. December 25	 1970. It must therefore logically follow that the serv ice rendered by them as Temporary Engineers on ad hoc basis prior to their recruitment as Assistant Engineers in 1975 could not be treated to be service in that class within the meaning of r.6(b) of the Class I Rules. Likewise	 r.8(2) which speaks of any service rendered as Temporary Engineer must be construed accordingly as meaning service rendered by a Temporary 617 Engineer recruited in the manner provided by the instruc tions contained in Manual of Administration issued under the 1941 Rules or recruited as such under the 1970 Rules. Last ly	 the decision in BaleShwar Das 's case does not lay down any proposition that persons employed on a purely ad hoc or fortuitous basis like respondents Nos. 1 & 2 are entitled as a matter of law to the benefit of their period of ad hoc service and the two later decisions in G.P. Doval & Ors.	 vs The Chief Secretary	 Government of Uttar Pradesh & Ors.	 ; and Narendra Chadha are of little assist ance. These submissions	 in our opinion	 must prevail. In reply	 the main contention of learned counsel for respondents Nos. 1 & 2 is that respondents Nos. 1 & 2 upon their absorption to the post of Assistant Engineer on a regular basis on April 21	 1975 were entitled to the benefit of the entire period of officiation as Temporary Engineers on an ad hoc basis i.e. the period from January 1971 and May 1969 to April 21	 1975 and the failure of the Government to count such period of their ad hoc service was per se arbi trary	 irrational and thus violative of articles 14 and 16(1) of the Constitution inasmuch as the service rendered by them as Temporary Engineers (ad hoc) was not for a short period intended to meet some emergent or unforeseen circumstances	 but to meet the exigencies of the service and there is no reason why the principles laid down in Baleshwar Das 's case should also not be extended in determining the seniority of such ad hoc employees vis a vis direct recruits. Secondly	 he contends that exercise of the power of relaxation of the condition of eight years ' service for purposes of eligibili ty conferred on the State Government under the proviso to r.6(b) is conditioned by the obligation to record reasons in writing which requirement was mandatory. There was failure on the part of the Government to record reasons therefor or to indicate any basis to show that such relaxation was in public interest. Further	 the words 'Class II Service ' in r.8(2) must bear the same meaning as the expression 'Class II Service ' as defined in r.2(5). The artificial definition of 'Class II Service ' introduced by amendment of r. 2(5) in 1975 was obviously to bring persons who were not Assistant Engineers i.e. members of Class II service within the zone of consideration for purposes of promotion to the post of Executive Engineer under r.6(b) of Class I Rules. Further more	 the State Government having relaxed the condition of 8 years ' service by recourse to the proviso to r.6(b)	 re spondents Nos. 1 & 2 were similarly situate as ' the appel lants and respondents Nos	5 24 as they were all recruited together as Assistant Engineers in Class II service in 1975 and they had all rendered about 31/2 years ' service in that class and therefore failure on the part of the State Govern ment to consider the case of. respondents Nos. 1 & 2 for 618 purposes of promotion to the post of Executive Engineer was tantamount to the total exclusion of a class within a class and was thus per se discriminatory. Lastly	 the action of the State Government in making ad hoc promotion of the appellants and respondents Nos. 5 24 was wholly mala fide. Learned counsel wanted us to draw an inference of mala fide from the fact that the Private Secretary to Chief Minister was present at a meeting held in the room of the Irrigation Minister where the list of promotion was settled. It is suggested that initially the names of respondents Nos. 1 & 2 figured in the list but later on wholly extraneous consider ations their names were deleted. It would be convenient at this stage to refer to the relevant provisions of the Punjab Service of Engineers Class I	 P.W.D. (Irrigation Branch) Rules	 1964	 as amended in 1975. The amendment effected in 1975 substituted a new r.2(5) for the existing r.2(5) and it defines the expression 'Class II Service ' as follows: "2(5). 'Class II Service ' shall	 for the purpose of promotion to the service	 comprises of members of the Haryana Service of Engi neers	 Class II (Irrigation Branch); Temporary Engineers	 Officiating Sub Divisional Officers and Officiating Assistant Design Engineers	 except those promoted in excess of the quota fixed under rule 6 of the Haryana Service of Engineers	 Class II	 Public Works Department (Irrigation Branch) Rules	 1970. " The qualifications of persons eligible for appointment are prescribed in r.6 which is in these terms: "6. Qualifications: No person shall be ap pointed to the service unless he (a) Possesses one of the University Degrees or other qualifications prescribed in Appendix B of these Rules; Provided that Government may waive this qualification in the case of a particular officer belonging to Class II Service; (b) In case of an appointment by promotion from Class II Service	 has completed in that class of service for a period of ten years from the commencement of these rules	 six years service and after that period eight years service; 619 Provided that if it appears to be necessary to promote an officer in the public interest	 the Government may	 for reasons to be recorded in writing either generally or in any individual case reduce the period of six or eight years to such extent as it may deem proper in consultation with the Finance De partment. Explanation: For the purpose of this clause in computing of the period of six or eight years any service rendered as a Temporary Engineer shall be taken into account". We may next set out r.8 which deals with the method of promotion: "8. Appointment by promotion: (1) A Committee consisting of the Chairman of the Public Service Commission and where the Chairman is unable to attend any other member of the Commission representing it	 the Secretary	 P.W.D. (Irrigation Branch) and the Chief Engineer	 Punjab	 P.W.D. Irrigation Branch shall be constituted. The Government shall prepare a list of eligible and suitable persons for promotions in order of their seniority in Class II Serv ice which shall be reckoned: (a) in the case of a member of the Haryana Service of Engineers	 Class 11 (Irrigation Branch) from the date of his continuous offi ciation as Sub Divisional Officer or Assistant Design Engineer or appointment as Temporary Engineer	 as the case may be: (b) in the case of a Temporary Engineer from the date of his appointment as such. " As a matter of construction	 the words 'Class II serv ice ' in r.8(2) introduced by amendment in 1975 must be construed to have the same meaning as the expression 'Class II service ' as defined in r.2(5). We find the language employed by the framers of the rules in the definition clause in r.2(5) has been departed from in the definition of the expression 'Class II service ' and it is generally but not always a fair presumption that the alteration in the language used in the new definition in r.2(5) was intention al. Prior to the amendment in 1975	 the expression	 'Class II Service ' as defined in r.2(5) meant the members of Class II service including Temporary Engineers. As the State stood 620 in need of many more Executive Engineers it became essential to take steps 3 recruit not only persons who strictly belong to Class II Service proper but also to bring within the zone of consideration others who are not members of Clause II Service e.g. Offg. Sub Divisional Officers and Offg. Assist ant Design Engineers who would not be so included. The key to the interpretation of the definition clause in r.2(5) is the words "for the purpose of promotion". The effect of the enlarged definition of Class II Service in r.2(5) is that these words when found in the Act must	 for the purpose of promotion	 be understood in that context in a certain sense i.e. to include not only members of Class II Service includ ing Temporary Engineers but also Offg. Sub Division Officers and Offg. Assistant Design Engineers who	 but for the inter pretation clause	 would not be so included. That would be in consonance with the purpose and object of the amendment. There is reason why 'the words 'Class II Service ' in r.8(2) introduced in 1975 must bear the same meaning as the expres sion 'Class II Service ' as defined in r.2(5) as both the provisions deal with the same subject i.e. promotion of members of Class II Service to the post of Executive Engi neer in Class I Service. The mode of promotion to the post of Executive Engineer is as laid down in r.8(2). Now	 r.8(1) remains unaltered. R.8(1) directs that a committee consist ing of the Chairman of the Public Service Commission or where the Chairman is unable to attend any other member of the Commission representing it	 Secretary to the. Govern ment	 P.W.D. (Irrigation Branch)	 and the Chief Engineer	 Punjab	 Irrigation Branch shall be constituted. Under r.8(2) introduced in 1975	 the Government has to prepare a list of eligible and suitable persons for promotion in order of their seniority in Class II Service which shall be reckoned (a) in the case of a member of the Haryana Service of Engi neers	 Class II	 Irrigation Branch	 from the date of his continuous officiation as Sub Divisional Officer or Assist ant Design Engineer or appointment as Temporary Engineer	 as the case may be. (b) In the case of a Temporary Engineer from the date of his appointment as such. These provisions can lead to no other conclusion but that the list of eligi ble and suitable persons for promotion has to be drawn not only comprising of regular members of Class II SerVice including Temporary Engineers in order of their seniority but also of Offg. Sub Divisional Officers or Offg. Assistant Design Engineers in that class of service from the date specified therein. Apparently	 the requirements of rr.8(1) and 8(2) have not been complied with. All that exists is the combined seniority list of Assistant Engineers belonging to Class II Service in order of their seniority prepared by the Public Service Commission which incidentally has never been challenged. 621 The meaning of the word 'as ' in the collocation of the words 'any service rendered as a Temporary Engineer ' in Explanation to r.6(b) of the Class I Rules must obviously mean 'in the capacity of '. In Dr. Asim Kumar Bose vs Union of India & Ors.	 ; the question was whether the appellant who was a Radiologist in the Maulana Azad Medical CoLlege which was a post belonging to Specialist Grade II could be appointed to the post of Professor of Radio Therapy in that College by direct recruitment under r.8(2) of the Central Health Service (Amendment) Rules	 1966. In 1971 there were certain amendments in the Rules prescribing the mode in which the posts of Professor and Associate Professor could be filled in and paragraphs 2(b) and 3 of Annexure I to the Second Schedule and sub r.(2a) to r.8 were inserted which brought about a change. These amend ments brought about a change inasmuch as they provided for a vertical channel of promotion to the teaching post upto the post of Associate Professor. At p.363 of the Report this Court referred to the report of the Third Pay Commission where it was observed at p. 173. "While the Specialists on the teaching side can hold posts of hospital specialists	 the latter cannot be promoted to teaching posts because of lack of teaching experience." Presumably	 the Ministry of Health on that view held that the word 'as ' in paragraphs 2(b) and 3 of Annexure I to the Second Schedule and sub r. (2a) of r.8 makes holding of a post in the cadre a condition precedent to the post of a Professor or an Associate Professor. In that context	 it was observed: Normally	 a Professor or an Additional Profes sor in a medical college or a teaching insti tution can be appointed by direct recruitment from amongst persons holding the post of Associate Professor or Assistant Professor in the concerned speciality in a medical college or a teaching institution having at least six years ' teaching experience out of 12 years; standing in the Grade through the Union Public Service Commission. An Associate Professor in the medical coLlege or a teaching institution can only be promoted from amongst persons holding the post of Reader or Assistant Pro fessor having at least five years ' teaching experience in ' the concerned special ity by the Departmental Promotion Committee. We are inclined to the view that the word "as" in the collocation of the words used "at least six years ' experience as Associate Professor/Assistant Profes 622 sor/Reader" in paragraph 2(b) and of the words "at least five years ' experience as Reader/Assistant Professor" in paragraph 3 and sub rule (2 A) of Rule 8 must be interpreted in its ordinary sense as meaning teaching experience gained "in the capacity of". In Black 's Law Dictionary	 5th Edn.	 p. 104	 the meaning of the word "as" as given is: "Used as an adverb	 etc.	 means like	 similar to	 of the same kind	 in the same manner	 in the manner in which." In Shorter Oxford Diction ary	 3rd Edn.	 p. 111	 the word "as" is stated to mean: "The same as	 in the character	 capacity	 role of". In spite of all this	 the contention of respondents Nos. 1 & 2 that they were entitled to the benefit of the period of service rendered by them as Temporary Engineer on an ad hoc basis w.e.f. January 2	 1971 and May 19	 1969 respectively prior to their appointment as Assistant Engineers on regular basis on April 21	 1975 for purposes of reckoning their eligibility under r.6(b) read with the Explanation thereto of the Class I Rules as also for purposes of their seniority in the cadre of Assistant Engineers	 cannot prevail. They were not recruited under paragraphs 8.312 to 8.316 of the Manual of Administration	 Public Works Department. In the erstwhile State of Punjab there was a distinct class of Engineers designated as Temporary Engineers. All persons appointed as Temporary Engineers had to face the Public Service Commission for selection to the post under rr.4 and 5 of the Punjab Service of Engineers	 Class II. P.W.D (Irrigation Branch) Rules	 1941. Under the Rules the term 'Temporary Engineer ' was defined in r.2(f) to mean an engi neer in the service of the Public Works Department	 Punjab whose appointment was temporary within the meaning of the Fundamental Rules	 was pensionable and who was not a member of any regular service. The word 'service ' as defined in r.2(g) of the Rules meant the Punjab Service of Engineers	 Class II	 Irrigation Branch. R.5 provided that no Temporaty Engineer could be taken into service or member of the Over seers Engineering Service	 Punjab promoted unless he had been declared by the Commission on the report of the Chief Engineer to be fit for the service	 was serving the Depart ment and held an appointment for not less than two years continuously before the date of entry into the service. Next came the Punjab Service of Engineers	 Class II	 P.W.D. (Irrigation Branch) Rules	 1970. The expression 'member of service ' was defined in r.2(12) to mean an offi cer appointed substantively to a cadre post. The definitions of the word 'service ' and of the term 623 'Temporary Engineer ' in r.2(15) and (16) remained the same except for the difference that the word 'temporary ' carried the meaning as given in the Civil Service Regulations in place of the Fundamental Rules. R.6 provided for the manner of recruitment of Temporary Engineers from different sources	 in the proportions and the order indicated. Sub r.(3) thereof provided that in case a candidate was not available from sources 1 and 3 i.e. by direct recruitment or by promotion	 and a person had to be appointed in public interest	 as a stop gap arrangement	 the period of service rendered by such person shall not be reckoned for the pur pose of seniority. Sub r. (4) provided that the Government could fill a short term vacancy in the exigencies of public service	 after recording specific reasons	 for the period not exceeding six months from the Overseers Engineering Service	 Irrigation Branch. It is quite apparent under these rules that appointment of respondents Nos. 1 & 2 as Tempo rary Engineers on an ad hoc basis was de hors the rules. It may seem to be some illogical that though respondents Nos. 1 & 2 were appointed as Temporary Engineers on an ad hoc basis	 they should be deprived of the period of their officiation as such till they were absorbed to the post of Assistant Engineer on a regular basis through the Public Service Commission on April 21	 1975. That is a legal conse quence which cannot be avoided on well settled principles. In their case the length of continuous officiation cannot be the basis for reckoning their seniority since they never became members of Class II Service prior to their absorp tion. On the terms of appointment of respondents Nos. 1 & 2	 it was specifically provided that their appointment was purely on an ad hoc basis for a period of six months from the date of their joining the post on a fixed salary of Rs.400+ allowances and that their services were liable to be terminated without notice. It was also specifically men tioned that the appointment as such Temporary Engineers on ad hoc basis would not count towards seniority or increment in their salary. It was further stated that the posts of Temporary Engineers in Class II Service would be advertised in due course by the Public Service Commission and that if they were not selected by the Commission	 their services would be terminated without notice They are also intimated that their inter se seniority among the Temporary Engineers so recruited would be in the order of merit in the list of candidates as settled by the Commission. It is common ground that respondents Nos. 1 & 2 were not recruited through the Public Service Commission. It was not till July 8	 1973 that the Secretary to the Commission conveyed to the State Gov ernment the approval of the Commission to the ad hoc ap pointment of 251 624 Temporary Engineers beyond the period of six months till regular appointments were made in the posts of Assistant Engineers through the Commission. These are the facts on which there is no doubt or difficulty as to the principles applicable. According to the accepted canons of service jurispru dence	 seniority of a person appointed must be reckoned from the date he becomes a member of the service. The date from which seniority is to be reckoned may be laid down by rules or instructions (a) on the basis of the date of appointment (b) on the basis of confirmation (c) on the basis of regula tion of service (d) on the basis of length of service	 or (e) on any other reasonable basis. It is well settled that an ad hoc or fortuitous appointment on a temporary or stop gap basis cannot be taken into account for the purpose of seniority even if the appointee was qualified to hold the post on a regular basis	 as such temporary tenure hardly counts for seniority in any system of service jurisprudence. In somewhat similar circumstances	 in the case of State of Gujarat vs C.G. Desai & Ors.	 [1974] 2 SCR 255 the question for consideration was whether in the case of Deputy Engi neers directly recruited through the Public Service Commis sion by competitive examination	 the service	 if any	 ren dered by them as officiating Deputy Engineers prior to their appointment to Class II Service i.e. during the pre selec tion period	 could be taken into account for purposes of their eligibility for promotion as Executive Engineers under r.7(2) of the Bombay Engineering Service Rules	 1960 which provided for a period of 7 years ' experience in Class II Service. The Government 's stand was that the service ren dered by the direct recruits prior to their appointment to the Class II Service could not be taken into account in computing their eligibility of 7 years ' experience in that class of service and the Court upheld the stand. It was contended on behalf of the promotees that if for promotion to the post of Executive 'Engineer in Class I Service the period of eligibility of 7 years ' experience in Class II Service was to start from the date of absorption in that class of service	 then	 for most of them there would be rare chance of ever getting promotion as officiating Executive Engineers and as many of them had less than 7 years to go before attaining the age of superannuation. The contention was that r.7(2) of the Rules did not permit discrimination between the promotees and direct recruits in the matter of computing 7 years ' service for further promotion as offici ating Executive Engineers. The contention was repelled on the ground that direct recruits and promotees in Class II Service constituted two distinct groups or classes and the classification was based on intelligible differentia	 and it was observed: 625 "If a person	 like any of the respondents	 to avoid the long tortuous wait leaves his posi tion in the 'never ending ' queue of Temporary/Officiating Deputy Engineers etc. looking for promotion	 and takes a short cut through the direct channel	 to Class II Serv ice	 he gives up once for all	 the advantages and disadvantages that go with the channel of promotion and accepts all the handicaps and benefits which attach to the group of direct recruits. He cannot	 after his direct recruit ment claim the benefit of his preselection service and thus have the best of both the worlds. It is well settled that so long as the classification is reasonable and the persons falling in the same class are treated alike	 there can be no question of violation of the constitutional guarantee of equal treatment. " In taking that view	 the Court avoided a doctrinaire ap proach and approached the problem from a pragmatic view. It was said: "If the claim of the respondents to the count ing of their pre selection service is conced ed	 it will create serious complications in running the administration; it will result in inequality of treatment rather than in remov ing it. If the pre selection service as Offi ciating Deputy Engineers of direct recruits having such service	 is taken into account for the purpose of promotion	 it would create two classes amongst the same group and result in discrimination against those direct recruits who had no such pre selection service to their credit. " It would be repugnant to all accepted concepts of serv ice jurisprudence if the claim of persons like respondents Nos. 1 & 2 who were employed as Temporary Engineers on ad hoc basis de hors the rules for six months at a time were extended the benefit of their continuous officiation as such ad hoc employees in reckoning their seniority vis a vis direct recruits in considering their eligibility under r.6(b) of the Class I Rules for promotion to a higher grade or post of Executive Engineer. In A.P.M. Mayakutty etc. vs Secretary	 Public Service Department	 the question was whether the period of service rendered by such ad hoc employees appointed under r. 10(a) (i)(1) of the Madras State & Subordinate Services Rules purely on an ad hoc basis and as matter of stop gap arrangement	 were enti tled to count for the purpose of seniority	 their period of service on ad hoc basis during which they served in a stop gap arrangement. It was held 626 that such service could not be taken into account for the purpose of seniority from the date of their initial appoint ment. The Court speaking through Chandrachud	 CJ. after referring to the provision contained in r. 10(a)(i)(1) of the Rules	 stated: "This provision contemplates the making of temporary appointments when it is necessary in the public interest to do so* to an emergency *owing which has arisen for filling a vacancy immediately. Such appointments	 in terms	 are permitted to made otherwise than in accordance with the rules. The letters of appointment issued to the appellants mention expressly that they were appointed under rule 10(a)(i)(1)	 that the appointments were "purely temporary necessitated on account of the non availability of regularly selected candidates conferring no claim for future appointment as Junior Engineers . and that the appointment is liable to be terminat ed at any time without previous notice. " In face of the provisions of the rule and the terms of the appointment it seems to us clear that the appellants were appointed purely as a matter of stop gap or emergency arrangement. Since such service cannot be taken into ac count for purposes of seniority	 the appel lants cannot contend that the entire service rendered by them from the date of their ini tial appointment must count for purposes of seniority. " The Court distinguished the case of C.P. Damodaran Nayar vs State of Kerala & Ors.	 ; on the ground that the temporary service rendered by a District Munsiff re cruited in a regular manner through the Public Service Commission could not	 by any stretch of imagination	 be considered to be purely as a matter of fortuitous or stop gap arrangement. The distinguishing features in Mayakutty 's case	 in the words of Chandrachud	 CJ. were: "The distinguishing feature of that case	 which is highlighted in the judgment of the Court	 is that the appellant therein was "appointed in a regular manner through the Public Service Commission" and therefore his appointment could not "by any stretch of imagination" be described as having been made to fill a purely stop gap or fortuitous vacu um. In our case the initial appointment was not only made without any reference to the Public Service Commission but the various rules and the terms of the appellants ' 627 appointment to which we have drawn attention show that the appellants were appointed purely as a matter of fortuitous or stop gap arrange ment. The concurrence of the Public Service Commission to the continuance of the appel lants in the posts filled by them first after the expiry of three months and then after the expiry of one year	 was obtained not with a view to regularising the appointments since their inception but for the purpose of meeting the requirements of a provision under which such concurrence is necessary to obtain if an appointment made without selection by the Public Service Commission is required for any reason to be continued beyond three months or a year. " That precisely is the case here. It must therefore be held that the period of service rendered by persons like respond ents Nos. 1 & 2 who were appointed on ad hoc basis purely as a stop gap arrangement for six months at a time de hors the rules	 cannot be considered for purposes of their seniority in Class II Service or in reckoning their eligibility of 8 years ' service in that class of service under r.6(b) of Class I Rules. We feel it necessary to emphasise that the principles laid down by this Court in the two cases of N.K. Chauhan and S.B. Patwardhan which were reiterated in Baleshwar Das 's case and subsequently followed in several other cases do not lay down any principle to the contrary. These cases are not an authority for the proposition relied upon. On the con trary	 they clearly proceed on the principle that persons appointed on an ad hoc basis or for fortuitous reasons or by stop gap arrangement	 constitute a class which is separate and distinct from those who are appointed to posts in the service in strict conformity with the rules of recruitment. In the case of S.B. Patwardhan	 Chandrachud	 CJ. observed: "We however hope that the Government will bear in mind the basic principle that if a cadre consists of both permanent and temporary employees	 the accident of confirmation cannot be an intelligible criterion for determining seniority as between direct recruits and promotees. All other factors being equal	 continuous officiation in a non fortuitous vacancy ought to receive due recognition in determining rules of seniority as between persons recruited from different sources	 so long as they belong to the same cadre	 628 discharge similar functions and bear similar responsibilities. " In Baleshwar Das 's case	 Krishna lyer	 J. affirmed the principle in his own charismatic and picturesque language: "We must emphasise that while temporary and permanent posts have great relevancy in regard to the career of government servants	 keeping posts temporary for long	 sometimes by annual renewals for several years	 and denying the claims of the incumbents on the score that their posts are temporary makes no sense and strikes us as arbitrary	 especially when both temporary and permanent appointees are func tionally identified. If	 in the normal course	 a post is temporary in the real sense and the appointee knows that his tenure cannot exceed the post in longevity	 there cannot be any thing unfair or capricious in clothing him with no fights. Not so	 if the post is	 for certain departmental or like purposes	 de clared temporary	 but it is within the ken of both the government and the appointee that the temporary posts are virtually long lived. It is irrational to reject the claim of the 'temporary ' appointee on the nominal score of the terminology of the post. We must also express emphatically that the principle which has received the sanction of this Court 's pronouncements is that officiating service in a post is for all practical purposes of sen iority as good as service on a regular basis. It may be permissible	 within limits	 for government to ignore officiating service and count only regular service when claims of seniority come before it	 provided the rules in that regard are clear and categories and do not admit of any ambiguity and cruelly arbi trary cut off of long years of service does not take place or there is functionally and qualitatively	 substantial difference in the service rendered in the two types of posts. While rules regulating conditions of service are within the executive power of the State or its legislative power under proviso to Article 309	 even so	 such rules have to be reasona ble	 fair and not grossly unjust if they are to survive the test of Articles 14 and 16. " We must also refer to the decision in A. Janardana vs Union of India & Ors.	 1 where Desai	 J. had occasion to observe: 629 "In other words after having rendered service in a post included in the service	 he is hanging outside the service	 without finding a berth in service	 whereas direct recruits of 1976 have found their place and berth in the service. This is the situation that stares into one 's face while interpreting the quota rota rule and its. impact on the service of an individual. But avoiding any humanitarian approach to the problem	 we shall strictly go by the relevant Rules and precedents and the impact of the Rules on the members of the service and determine whether the impugned seniority list is valid or not. But	 having done that we do propose to examine and expose an extremely undesirable	 unjust and inequita ble situation emerging in service jurispru dence from the precedents namely	 that a person already rendering service as a promotee has to go down below a person who comes into service decades after the promotee enters the service and who may be a schoolian	 if not in embryo	 when the promotee on being promoted on account of the exigencies of service as re quired by the Government started rendering service. A time has come to recast service jurisprudence on more just and equitable foundation by examining all precedents on the subject to retrieve this situation. " To the same effect are the decisions in O.P. Singla vs Union of India	 ; ; G	S. Larnba vs Union of India	 ; P.S. Mahal vs Union of India	 ; and Pran Krishna Goswami & Ors. vs State of West Bengal & Ors. 	 ; It must now be taken as well established after these decisions that in the absence of any other valid principle of seniority	 the inter se seniority between direct recruits and promotees should as far as possible be determined by the length of continuous service whether temporary or permanent in a particular grade or post (this should exclude periods for which an appoint ment is held in a purely stop gap or fortuitous arrangement). No doubt	 there are certain observations in the two cases of G.P. Doral and Narender Chadha which seem to run counter to the view we have taken	 but these deci sions turned on their own peculiar facts and are therefore clearly distinguishable and they do not lay down any rule of universal application. For all these reasons	 the appeal succeeds and is al lowed. The judgment and order of the High Court quashing the impugned notification of the State Government dated December 20	 1978 making 630 ad hoc promotions of the appellants and respondents Nos. 5 24 are set aside. Instead	 we direct that the impugned order of the State Government making ad hoc promotions of 62 Assistant Engineers including the appellants and respondents Nos. 5 24 as officiating Executive Engineers will stand and they shall continue to function as such	 subject to the terms and conditions contained in the aforesaid order till the process of making appointments by promotion to these posts is completed. We hope and trust that the State Govern ment will strike a just balance between the competing claims of these 62 Assistant Engineers promoted as Executive Engi neers on ad hoc basis	 and persons like respondents Nos. 1 & 2 appointed as Temporary Engineers on an ad hoc basis who could at the most claim that they should be given the bene fit of the period of service from April 21	 1975 when they were recruited as Assistant Engineers through the Public Service Commission	 provided they satisfy the test of eligi bility of 8 years ' experience in that class of service	 while considering the cases of all eligible members of Class II Service for promotion to the post of Executive Engineer in Class I Service in accordance with law and will complete the process of appointment within six months from today. There shall be no order as to costs. S.R. Appeal allowed.

Haryana Service of Engineers	 Class II	 Public Works Department (Irrigation Branch) Rules relating to recruitment etc. of Asst. Engineers and Haryana Service of Engineers Class I	 Public Works Department (Irrigation Branch) relat ing to Executive Engineers came into force in 1970 and 1964 respectively. Respondent No. 2	 B.L. Gupta and Respondents Nos. B.S. Jain were appointed as temporary engineers (ad hoc) with effect from 19.5.1969 and 2.1.1971 respectively	 the former sponsored by the Employment Exchange and the latter with reference to an advertisement in the newspapers. Their appointments were de hors the said Class II Rules to meet the exigencies of service. In the letters of appoint ment issued to them it was specified (i) that their appoint ment was purely on an ad hoc basis for a period of six months from the date of their joining the post on a fixed salary of Rs.400 plus allowances and their services were terminable without notice; (ii) that the appointment would not entitle them to any seniority or other benefit under the service rules for the time being in force and would also not count towards increment in their salary; (iii) that the posts of Tempor 604 ary Engineers in Class II service would be advertised in the course by the Haryana Public Service Commission and they should apply for such posts through the Commission	 and that if they were not selected by the Commission	 their services would be liable to be terminated without notice; and (iv) that their inter se seniority among the Temporary Engineers would be in the order of merit in the list of candidates as settled by the Commission. The services of respondents Nos. 1 and 2 were however continued by the State Government from time to time	 six months at a time till the Secretary	 Haryana Public Service Commission by his letter dated July 8	 1973 addressed to the Commissioner and Secretary to the State Government of Haryana	 Public Works Department (Irri gation Branch) conveyed the approval of the Commission to the ad hoc appointment of 251 Temporary Engineers beyond the period of six months till regular appointments were made to the posts through the Commission. Accordingly both these respondents continued to hold the posts of Temporary Engi neers on ad hoc basis till the end of the year 1974 i.e. till they were recruited as Asst. Engineers through the Public Service Commission on April 21	 1975 on regular basis. In the letter of appointment issued by the Commis sioner and Secretary to Government of Haryana (Irrigation & Power Department) dated January 13	 1975 it was specified again that inter se seniority of Asst. Engineers would be determined on the basis of the combined merit list prepared by the Public Service Commission. In the combined merit list prepared by the Commission	 respondents Nos. 1 and 2 were placed very much below the appellants and respondents Nos. 5 24 being at serial Nos. 148 and 150 respectively. The State Government of Haryana by order dated December 20	 1978 promoted 62 Asst. Engineers including the appel lants and respondent Nos. 5 24 as Executive Engineers on a purely ad hoc basis for a period of six months subject to certain terms and conditions	 namely; (i) the promotions were subject to the approval of the Public Service Commis sion as also to the claims of other officers; (ii) such promotions were not to give any right to the officers for being appointed on a substantive basis as Executive Engi neers; and (iii) such of the officers as had not passed the departmental professional and revenue examinations were required to pass such examination within a period of one year or otherwise they were liable to be reverted to their original post. These ad hoc promotions of the appellants and respondents Nos. 5 24 were made in relaxation of the provi sions contained in rr. 6(b) and 15 of the Haryana Service of Engineers	 Class I Public Works Department (irrigation Branch) Rules	 1964. Presumably	 the State Government ex cluded from consideration the case of respondents Nos. 1 and 2 for 605 promotion because in the combined seniority list they ranked below the appellants and respondents Nos. 5 24 being placed at serial Nos. I48 and 150 respectively. The said ad hoc promotions to Class I posts were as sailed by respondents I and 2 by a petition under Article 226. A learned Single Judge by his judgment dated 8.10.1980 quashed the impugned order of the State Government making the said ad hoc promotions and directed the State Government to reach a decision afresh as regards the ad hoc promotions with advertence to the observations made by him. Thereupon	 the appellants preferred an appeal under clause 10 of the Letters Patent but the appeal was dismissed in limine by the Division Bench	 by its order dated 6.11.1980. The appel lants ' contention that the appointment of respondents Nos. I and 2 as Temporary Engineers on an ad hoc basis was contrary to para 8.312 of the Manual of Administration and therefore the period during which they worked as Temporary Engineers (ad hoc) could not be taken into consideration	 was repelled by the Bench on the ground that no such point was taken before the learned Single Judge. Hence the appeal by special leave. Allowing the appeal	 the Court HELD: 1. The High Court ought not to have exercised their powers under Article 226 of the Constitution and entertained the writ petition of respondents I and 2 partic ularly when the impugned order of the State Government making promotion of the 62 Asst. Engineers including the appellants and respondents 5 24 as Executive Engineers was purely on an ad hoc basis for a period of six months and expressly made subject to the rights of other officers. Instead of interfering with the impugned order of the State Government the proper course for the High Court should have been to issue a direction to the State Government to consid er the cases of the eligible officers including respondents Nos. I and 2 for ad hoc promotion as Executive Engineer if their turn was due for such promotion according to their placement in the seniority list and it should have in the meanwhile allowed the appellants and respondents Nos. 5 24 to continue in their posts as Executive Engineers (ad hoc) subject to the condition that while considering their cases for promotion the State Government would not take that circumstance into consideration that they had continued to function as Executive Engineers on an ad hoc basis. [613G H; 614A C] 1.2 Rule 15 of the Punjab/Haryana Service of Engineers Class I P.W.D. (Irrigation Branch) Rules	 1970 in terms provides that the 606 departmental professional and revenue examinations for purposes of promotion to the Class I service have to be passed within such period as may be prescribed. The word 'prescribed ' in Rule 15 clearly empowers the State Govern ment to provide for the period during which the promoted officers had to pass the departmental test. In terms of that rule	 the State Government by the impugned order directed that the officers who had not passed the departmental pro fessional and revenue examinations were required to pass such examinations within a period of one year otherwise they were liable to be reverted to their original post. There fore	 no question of relaxation under Rule 22 arose. [613C E] 2.1 The period of service rendered by persons like respondents Nos. 1 and 2 who were appointed on ad hoc basis purely on a stop gap arrangement for six months at a time de hors the rules	 cannot be considered for purposes of their seniority in Class II service or in reckoning their eligi bility of 8 years ' service in that class of service under Rule 6(b) of the Class I Rules. [625F G] 2.2. As a matter of construction the words "Class II service" in Rule 8(2) introduced by amendment in 1975 must be construed to have the same meaning as the expression "Class II service" as defined in Rule 2(5). Prior to the amendment in 1975	 the expression	 "Class II Service" as defined in Rule 2(5) meant the members of Class II service including Temporary Engineers. The key to the interpretation of the definition clause in Rule 2(5) is the words "for the purpose of promotion. " The effect of the enlarged definition of Class II service in Rule 2(5) is that these words when found in the Act must	 for the purpose of promotion	 be understood in that context in a certain sense i.e. to in clude not only members of CIass II Service including Tempo rary Engineers but also Offg. Sub Division Officers and Offg. Assistant Design Engineers who	 but for the interpre tation clause	 would not be so included. That would be in consonance with the purpose and object of the amendment. [619G H; 620B C] 2.3 The meaning of the word "as" in the collocation of the words "any service rendered as a Temporary Engineer" in Explanation to Rule 6(b) of the Class I Rules must obviously mean "in the capacity of". [621A B] Dr. Asim Kumar Bose vs Union of India & Ors. 	 ; 	 applied. 2.4 It is true that though respondents Nos. 1 and 2 were 607 appointed as Temporary Engineers on an ad hoc basis	 they should be deprived of the period of their officiation as such till they were absorbed to the post of Assistant Engi neer on a regular basis through the Public Service Commis sion on April 21	 1975. That is a legal consequence which cannot be avoided on well settled principles. [623D E] 2.5 According to the accepted cannos of service juris prudence	 seniority of a person appointed must be reckoned from the date he becomes a member of the service. The date from which seniority is to be reckoned may be laid down by rules or instructions (a) on the basis of the date of ap pointment (b) on the basis of confirmation (c) on the basis of regularisation of service (d) on the basis of length of service; or (e) on any other reasonable basis. It is well settled that an ad hoc or fortuitous appointment on a tempo rary or stop gap basis cannot be taken into account for the purpose of seniority even if the appointee was qualified to hold the post on a regular basis	 as such temporary tenure hardly counts for seniority in any system of service juris prudence. [624B D] 2.6 It must now be well taken as well established that after the Supreme Court decisions from N.K. Chauhan to Baleswar Das in the absence of any other valid principle of seniority	 the inter se seniority between direct recruits and promotees should as far as possible be determined by the length of continuous service whether temporary or permanent in a particular grade or post (this should exclude periods for which an appointment is held in a purely stop gap or fortuitous arrangement). These decisions particularly that in Baleshwar Das 's case clearly lay down that ordinarily and in the absence of any specific rule of seniority governing the cadre or service	 the length of continuous officiation should be counted in reckoning seniority as between direct recruits and promotees. These authorities nowhere lay down that the same principle i.e. the length of continuous offi ciation must be the sole guiding factor and the only crite rion in determining seniority of such adhoc employees vis a vis direct recruits. On the contrary	 they clearly proceed on the principle that persons appointed on an ad hoc basis or for fortuitous reasons or by stop gap arrangement	 constitute a class which is separate and distinct from those who are appointed to posts in the service in strict conform ity with the rules of recruitment. [629E G; 627.E F] N.K. Chauhan & Ors. vs State of Gujarat & Ors. 	 ; ; S.B. Patwardhan & Ors. vs State of Maharashtra & Ors. 	 ; and Baleshwar Das & Ors. vs State of Uttar Pradesh & Ors. 	 [1981] 1 SCR 449	 discussed. 608 A.P.M. Mayakutty etc. vs Secretary	 Public Service Department	 ; State of Gujarat vs C.G. Desai Ors. ; 	 ; O.P. Singla vs Union of India	 ; ; G.S. Lamba vs Union of India	 ; P.S. Mahal vs Union of India	 ; ; and Pran Krishna Goswami & Ors. vs State of West Bengal & Ors. 	 ; 	 referred to. Narendra Chadha & Ors. vs Union of India & Ors. 	 ; ; G.P. Doval & Ors. vs The Chief Secretary	 Govern ment of Uttar Pradesh & Ors.	 ; ; and C.P. Damodaran Nayar vs State of Kerala & Ors.	 ; 	 distinguished.