NY CPLR § 203 (2021)
2021 New York Laws CVP - Civil Practice Law and Rules Article 2 - Limitations of Time 203 - Method of Computing Periods of Limitation Generally.

§  203.  Method  of  computing  periods  of  limitation generally. (a) Accrual of cause of action and interposition of claim. The  time  within which  an  action  must  be  commenced,  except  as  otherwise expressly prescribed, shall be computed from the time the cause of action  accrued to the time the claim is interposed.  (b) Claim in complaint where action commenced by service. In an action which  is  commenced  by  service,  a claim asserted in the complaint is interposed against the defendant or a co-defendant  united  in  interest with such defendant when:   1. the summons is served upon the defendant; or   2.  first  publication  of  the  summons against the defendant is made pursuant to an order, and publication is subsequently completed; or   3. an order for a provisional remedy other than attachment is granted, if, within thirty days  thereafter,  the  summons  is  served  upon  the defendant  or  first publication of the summons against the defendant is made pursuant to an order and publication is subsequently completed, or, where the defendant dies within thirty days after the order  is  granted and  before  the  summons is served upon the defendant or publication is completed, if the summons is served upon  the  defendant's  executor  or administrator  within  sixty  days  after  letters  are issued; for this purpose seizure of a chattel in an action to  recover  a  chattel  is  a provisional remedy; or   4.  an  order  of  attachment  is granted, if the summons is served in accordance with the provisions of section 6213; or   5. the summons is delivered to the sheriff of that county outside  the city  of  New  York or is filed with the clerk of that county within the city of New York in which the defendant resides, is employed or is doing business, or if none of the foregoing is known to  the  plaintiff  after reasonable  inquiry,  then of the county in which the defendant is known to have last resided, been employed or been engaged in business,  or  in which  the  cause of action arose; or if the defendant is a corporation, of a county in which it may be served or in which the  cause  of  action arose; provided that:  (i)  the  summons is served upon the defendant within sixty days after the period of limitation would have expired but for this provision; or  (ii) first publication of the summons against the  defendant  is  made pursuant  to  an  order within sixty days after the period of limitation would  have  expired  but  for  this  provision   and   publication   is subsequently completed; or  (iii)   the  summons  is  served  upon  the  defendant's  executor  or administrator within sixty days after  letters  are  issued,  where  the defendant  dies  within  sixty days after the period of limitation would have expired but for this provision and before  the  summons  is  served upon the defendant or publication is completed.   6.  in an action to be commenced in a court not of record, the summons is delivered for service upon the defendant to any officer authorized to serve it in a county, city or town in which the  defendant  resides,  is employed  or  is doing business, or if none of the foregoing be known to the plaintiff after reasonable inquiry, then in a county, city  or  town in  which defendant is known to have last resided, been employed or been engaged in business, or, where the defendant  is  a  corporation,  in  a county, city or town in which it may be served, if the summons is served upon  the  defendant  within  sixty  days after the period of limitation would have expired but for this provision; or, where the defendant  dies within  sixty days after the period of limitation would have expired but for this provision and before the summons is served upon the  defendant, if the summons is served upon his executor or administrator within sixty days after letters are issued.  (c)  Claim in complaint where action commenced by filing. In an action which is commenced by filing, a  claim  asserted  in  the  complaint  is interposed  against  the  defendant or a co-defendant united in interest with such defendant when the action is commenced.  (d)  Defense  or counterclaim. A defense or counterclaim is interposed when a pleading containing it is served. A defense  or  counterclaim  is not  barred  if it was not barred at the time the claims asserted in the complaint were interposed, except that if the  defense  or  counterclaim arose  from  the transactions, occurrences, or series of transactions or occurrences, upon which a claim asserted in the complaint depends, it is not barred to the extent of the demand in the complaint  notwithstanding that it was barred at the time the claims asserted in the complaint were interposed.  (e)  Effect  upon  defense  or  counterclaim  of termination of action because of death or by dismissal or voluntary  discontinuance.  Where  a defendant  has served an answer containing a defense or counterclaim and the action  is  terminated  because  of  the  plaintiff's  death  or  by dismissal  or  voluntary  discontinuance, the time which elapsed between the commencement and termination of the action is not a part of the time within which an action must be commenced to recover upon  the  claim  in the  defense  or  counterclaim  or  the time within which the defense or counterclaim  may  be  interposed  in  another  action  brought  by  the plaintiff or his successor in interest.  (f) Claim in amended pleading. A claim asserted in an amended pleading is deemed to have been interposed at the time the claims in the original pleading  were  interposed,  unless  the original pleading does not give notice of the transactions, occurrences, or series  of  transactions  or occurrences, to be proved pursuant to the amended pleading.  (g) 1. Time computed from actual or imputed discovery of facts. Except as  provided in article two of the uniform commercial code or in section two hundred fourteen-a of this chapter, where the time within  which  an action  must  be  commenced  is  computed  from the time when facts were discovered or from the time when facts could with  reasonable  diligence have  been  discovered, or from either of such times, the action must be commenced within two years after such actual  or  imputed  discovery  or within  the  period otherwise provided, computed from the time the cause of action accrued, whichever is longer.   2. Notwithstanding paragraph one of this subdivision, in an action  or claim  for medical, dental or podiatric malpractice, where the action or claim is based upon the alleged negligent failure to diagnose cancer  or a  malignant  tumor,  whether  by  act  or omission, for the purposes of sections fifty-e and fifty-i of the general municipal law,  section  ten of  the  court  of  claims  act,  and  the  provisions  of any other law pertaining to the commencement of an action or special proceeding, or to the  serving  of  a  notice  of  claim  as  a  condition  precedent   to commencement  of an action or special proceeding within a specified time period, the time in which to commence an action or special proceeding or to serve a notice of claim shall not begin to run  until  the  later  of either (i) when the person knows or reasonably should have known of such alleged  negligent  act  or omission and knows or reasonably should have known that such alleged negligent act or  omission  has  caused  injury, provided,  that such action shall be commenced no later than seven years from such alleged negligent act or omission, or (ii)  the  date  of  the last  treatment  where  there  is  continuous treatment for such injury, illness or condition.