Court Opinion

ID: 9373883
Source: CourtListenerOpinion
Date Created: 2023-02-22 16:09:49.348286+00
Date Added: 2024-06-11T17:16:43.839154
License: Public Domain

Case: 21-1787    Document: 50    Page: 1   Filed: 02/22/2023

   United States Court of Appeals
       for the Federal Circuit
                 ______________________

                   JOHN C. KLUGE,
                      Petitioner

                            v.

     DEPARTMENT OF HOMELAND SECURITY,
                  Respondent
            ______________________

                       2021-1787
                 ______________________

    Petition for review of the Merit Systems Protection
 Board in No. DC-4324-20-0246-I-1.
                 ______________________

                Decided: February 22, 2023
                 ______________________

    JAMES RENNE, Arlington, VA, argued for petitioner.

     GEOFFREY MARTIN LONG, Commercial Litigation
 Branch, Civil Division, United States Department of Jus-
 tice, Washington, DC, argued for respondent. Also repre-
 sented by BRIAN M. BOYNTON, CLAUDIA BURKE, MARTIN F.
 HOCKEY, JR.
                 ______________________

  Before DYK, TARANTO, and CUNNINGHAM, Circuit Judges.
 CUNNINGHAM, Circuit Judge.
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 2                                              KLUGE   v. DHS

      John Kluge appeals from decisions of the Merit Sys-
 tems Protection Board denying class certification, dismiss-
 ing the Office of Personnel Management as a respondent,
 and finding that his former employer, the Department of
 Homeland Security, owed him differential pay in the
 amount of $274.37 plus interest under 5 U.S.C. § 5538. We
 affirm.
                      I.     BACKGROUND
     Mr. Kluge, a commissioned officer in the United States
 Army Reserve and a civilian employee of the Department
 of Homeland Security (“DHS”), was ordered to report to ac-
 tive duty in January 2011 in support of a contingency op-
 eration, Operation Enduring Freedom. J.A. 223; Pet’r’s Br.
 8–10. He was ordered to active duty under 10 U.S.C.
 § 12301(d), which provides for voluntary active duty of re-
 servists. J.A. 223. Because of his service, he was absent
 from his DHS job from January 15 to July 30, 2011. J.A.
 225; Pet’r’s Br. 9.
     For the first few weeks of this period, Mr. Kluge was on
 paid military leave from his job at DHS. Pet’r’s Br. 10.
 From February 27 until July 30, 2011, Mr. Kluge was on
 unpaid leave. Id.; J.A. 465. DHS did not pay him for any
 of those days except for the July 4 holiday. Pet’r’s Br. 10
 n.8; J.A. 465.
     In 2019, Mr. Kluge filed an appeal before the Board,
 seeking to recover differential pay under 5 U.S.C. § 5538
 for himself and similarly situated service members em-
 ployed by the federal government. J.A. 43–60. He named
 the Office of Personnel Management (“OPM”) as the re-
 spondent in that appeal. J.A. 43.
     The administrative judge assigned to Mr. Kluge’s ap-
 peal denied class certification and substituted DHS for
 OPM as the respondent. J.A. 6. DHS and Mr. Kluge then
 stipulated that he was eligible for differential pay. J.A.
 464. The administrative judge determined that DHS owed
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 KLUGE   v. DHS                                             3

 Mr. Kluge $274.37 plus interest. J.A. 15–20. The admin-
 istrative judge’s decision became the Board’s final decision
 under 5 C.F.R. § 1201.113.
     Mr. Kluge appeals from that final decision. We have
 jurisdiction to consider his appeal under 28 U.S.C.
 § 1295(a)(9).
                        II.    DISCUSSION
     Mr. Kluge raises three issues on appeal. First, he as-
 serts that the administrative judge abused her discretion
 in denying class certification. Pet’r’s Br. 16–17. Second, he
 argues that the administrative judge erred in dismissing
 OPM as a party. Pet’r’s Br. 16. Finally, he contends that
 the administrative judge miscalculated the amount of dif-
 ferential pay he is owed. Pet’r’s Br. 17. We address each
 of these issues in turn.
                  A. Denial of Class Certification
     Before the Board, Mr. Kluge alleged that federal agen-
 cies improperly denied differential pay to him and a class
 of potentially over 3,000 reservists employed by the federal
 government across all agencies who may have been on vol-
 untary active duty in support of a contingency operation
 under 10 U.S.C. § 12301(d). J.A. 57–59, 206–17. He al-
 leged that all federal civilian employers improperly denied
 reservists differential pay by following OPM guidance, first
 promulgated in December 2009, that states that “voluntary
 active duty under 10 U.S.C. [§] 12301(d)” does not qualify
 for differential pay. J.A. 55–56; J.A. 478, 495.
     The administrative judge denied class certification.
 J.A. 6. She first found that certification of the class would
 implicate the privacy rights of potential class members “as
 certification of the class would reveal to all class members
 individual employees pay information and potentially
 other Privacy Act protected information.” J.A. 5. She also
 found that the putative class lacked commonality because
 the class would come from various government agencies,
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 4                                                KLUGE   v. DHS

 but Mr. Kluge had not alleged that all agencies had acted
 in the same manner or for the same reasons. Id. She fur-
 ther found that identification of class members would re-
 quire detailed analysis of each potential member’s
 employment and deployment records—records spanning
 over a decade. Id. Finally, she addressed Mr. Kluge’s con-
 cern about judicial efficiency, noting that the Board has
 heard individual claims similar to the claim posed by Mr.
 Kluge since 2015 and has not suffered a deluge of cases.
 J.A. 5–6.
      On appeal, Mr. Kluge argues that the administrative
 judge abused her discretion in denying class certification
 because certification of a class is the only fair and efficient
 way to address OPM’s allegedly incorrect guidance. Pet’r’s
 Br. 25–37. He argues that the administrative judge’s fac-
 tual findings regarding privacy concerns, the lack of com-
 monality, the inefficiency of identifying class membership,
 and the unlikely possibility of opening the floodgates of lit-
 igation before the Board are incorrect. Id. Finally, he ar-
 gues that the administrative judge erred by not addressing
 all the factors for class certification named in Federal Rule
 of Civil Procedure 23 and by considering privacy, which is
 not identified as a factor in Rule 23 or in other pertinent
 statutes or regulations. Id. at 25.
      We set aside Board decisions only if they are “(1) arbi-
 trary, capricious, an abuse of discretion, or otherwise not
 in accordance with law; (2) obtained without procedures re-
 quired by law, rule, or regulation having been followed; or
 (3) unsupported by substantial evidence.”          5 U.S.C.
 § 7703(c); see also 38 U.S.C. § 4324(d)(1) (establishing our
 ability to review the Board’s Uniformed Services Employ-
 ment and Reemployment Rights Act decisions in accord-
 ance with 5 U.S.C. § 7703). We review the Board’s denial
 of class certification for abuse of discretion. Certain For-
 mer CSA Emps. v. Dep’t of Health & Hum. Servs., 762 F.2d
 978, 986 (Fed. Cir. 1985). The Board “abuses its discretion
 when the decision is based on an erroneous interpretation
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 KLUGE   v. DHS                                               5

 of the law, [based] on factual findings that are not sup-
 ported by substantial evidence, or represents an unreason-
 able judgment in weighing relevant factors.” O’Farrell v.
 Dep’t of Def., 882 F.3d 1080, 1083 (Fed. Cir. 2018) (quoting
 Tartaglia v. Dep’t of Veterans Affs., 858 F.3d 1405, 1407–
 08 (Fed. Cir. 2017) (internal quotation marks omitted)).
     We conclude that the administrative judge did not
 abuse her discretion in denying class certification. The ad-
 ministrative judge did not err by not considering all criteria
 in Rule 23 or by considering criteria not specifically listed
 in Rule 23. Mr. Kluge has not shown that the administra-
 tive judge erred in finding that putative class members
 lack commonality or that identifying class members and
 adjudicating their claims as a class would not be a fairer or
 more efficient way to proceed. Although we disagree with
 the administrative judge’s finding that certification of the
 class would require revealing all class member’s private
 pay information to all other class members, that error does
 not compel us to reverse the denial of class certification.
 We further explain each of these conclusions below.
            i.     Federal Rule of Civil Procedure 23
     As an initial matter, the Board, unlike district courts,
 is not bound by Federal Rule of Civil Procedure 23 in de-
 termining whether to grant or deny class certification.
 Compare 5 C.F.R. § 1201.27(c), with Goldman Sachs Grp.,
 Inc. v. Ark. Tchr. Ret. Sys., 141 S. Ct. 1951, 1960–61 (2021)
 (“As we have repeatedly explained, a court has an obliga-
 tion before certifying a class to ‘determin[e] that Rule 23 is
 satisfied, even when that requires inquiry into the merits.’”
 (alteration in original) (quoting Comcast Corp. v. Behrend,
 569 U.S. 27, 35 (2013)). Rather, 5 C.F.R. § 1201.27(c) in-
 structs that the applicable provisions of the Federal Rules
 of Civil Procedure may “guide[] but not control[]” the ad-
 ministrative judge’s decision.         And under 5 C.F.R.
 § 1201.27(a), an administrative judge should “hear the case
 as a class appeal if . . . she finds that a class appeal is the
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 6                                              KLUGE   v. DHS

 fairest and most efficient way to adjudicate the appeal,”
 among other requirements. Thus, we reject Mr. Kluge’s ar-
 gument that the administrative judge was required to ad-
 dress any factors identified in Rule 23 or was constrained
 to only considering those factors.
                      ii.    Commonality
      The administrative judge did not err in finding a lack
 of commonality. Mr. Kluge identifies the allegedly incor-
 rect OPM guidance statement that “qualifying active duty
 does not include voluntary active duty under 10 U.S.C.
 [§] 12031(d)” as the unifying legal issue. Pet’r’s Br. 29. He
 asserts that all federal employers uniformly adhered to the
 OPM guidance. Id.
     The evidence Mr. Kluge presents on appeal of this al-
 leged universal denial of differential pay to reservists who
 participated in voluntary active duty under 10 U.S.C.
 § 12301(d) are statements that the government made in a
 parallel case before the United States District Court for the
 District of Columbia. 1 Pet’r’s Reply Br. 6–7. These state-
 ments are:
     OPM’s policy guidance, which is directed to and re-
     lied upon by the Federal agencies that must make
     the payments to qualifying employees, has been
     updated four times . . . but none of the revisions
     have altered the 2009 definition of “qualifying ac-
     tive duty.”
 J.A. 571; see also J.A. 572, 575, and

     1   This parallel litigation has since been transferred
 to the United States Court of Federal Claims. Order
 Granting Plaintiff’s Motion to Transfer, Kluge v. United
 States, No. 1:19-cv-02618 (D.D.C. Aug. 24, 2021), ECF No.
 51.
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 KLUGE   v. DHS                                             7

     [L]egal consequences clearly flowed from the deci-
     sion, which was included in OPM’s Policy Guidance
     Regarding Reservist Differential Under 5 U.S.C.
     [§] 5538, and that instructed federal agencies on
     how to apply the differential pay statute, and thus
     affected the circumstances under which federal em-
     ployees could qualify for payments under the stat-
     ute.
 J.A. 573, 574, 576; Pet’r’s Reply Br. 6–7. Mr. Kluge asks us
 to take judicial notice of these statements, which he char-
 acterizes as government admissions. Pet’r’s Reply Br. 6–7.
     We have already partially decided the issue of whether
 to take judicial notice of these statements. Order, Kluge v.
 Dep’t of Homeland Sec., No. 21-1787 (Fed. Cir. Oct. 21,
 2021), ECF No. 30. After Mr. Kluge filed a motion to take
 judicial notice of the filings containing these statements,
 we explained that we “may take judicial notice of the fact
 that these pleadings were filed at the district court by the
 government.” Id. But “[t]he relevance of such material . . .
 will be left to the merits panel.” Id.
      We determine that the scant evidence provided by
 these statements does not show any error in the adminis-
 trative judge’s finding that the proposed class lacks com-
 monality. Mr. Kluge’s allegation that all federal agencies
 followed OPM guidance is undercut by DHS’s decision not
 to follow the OPM guidance in Mr. Kluge’s case. After the
 administrative judge denied class certification, DHS
 agreed that Mr. Kluge was eligible for differential pay. J.A.
 464. And, as the administrative judge noted, “OPM’s guid-
 ance is just that, guidance.” J.A. 15. It is not binding on
 DHS or any of the other agencies that might have employed
 a putative class member. Out of every member of the pu-
 tative class, we only have information as to Mr. Kluge, and
 his case lacks the very feature—his employing agency ad-
 hering to OPM guidance—he asserts is common to the
 class. The government’s statements in parallel litigation
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 8                                                KLUGE   v. DHS

 that federal agencies relied on the OPM guidance and that
 the guidance affected the circumstances under which fed-
 eral employees could qualify for payments cannot sur-
 mount the contradictory evidence that DHS did not follow
 OPM’s guidance in Mr. Kluge’s case.
     We conclude that Mr. Kluge has not identified any er-
 ror in the administrative judge’s determination that the
 putative class lacks commonality.
                         iii.   Efficiency
     Next, we reject Mr. Kluge’s argument that the admin-
 istrative judge erred in finding that it would not be efficient
 to determine class membership. The administrative judge
 explained that identifying all federally employed reservists
 and reviewing their employment and deployment records
 to determine if they qualified for a differential payment
 that they were not paid would not be fairer or more efficient
 than individual adjudication. J.A. 5. Mr. Kluge asserts
 that the “inefficient and unproductive” method of identify-
 ing class members addressed by the administrative judge
 is not a necessary or reasonable approach. Pet’r’s Br. 31.
 He asserts that the Department of Defense keeps all rele-
 vant deployment information in its Defense Finance and
 Accounting Service databases and that databases of civil-
 ian payroll records are kept by either OPM, the Depart-
 ment of Defense, or the National Finance Center. Id. at
 31–32. He asserts that it would be “relatively simple for
 the Government” to determine class membership by com-
 paring these databases. Id. at 32.
     We do not find this argument persuasive. Mr. Kluge
 merely speculates that all required information is stored in
 easily accessible central databases and that it would be rel-
 atively simple to use those databases to determine class
 membership. Indeed, OPM told the administrative judge
 that it did not have any civilian pay records for Mr. Kluge—
 those records were ultimately obtained from his employer,
 DHS. J.A. 116, 464. Contrary to Mr. Kluge’s assertion, it
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 KLUGE   v. DHS                                            9

 appears that individual pay records would have to be col-
 lected from each putative class member’s federal employer.
 Mr. Kluge provided no evidence that those records would
 be in a format that is easily compared to military records.
 Thus, we conclude that the administrative judge did not err
 in finding that a class action would not be fairer or more
 efficient.
                         iv.     Privacy
     Next, we consider the administrative judge’s finding
 that certification of the class would require revealing the
 private pay information of all class members to all other
 class members. J.A. 5. We conclude this finding is unsup-
 ported. We recognize that class members’ private infor-
 mation may need to be shared with class counsel. 2 But we
 are aware of no reason why class members’ private infor-
 mation would need to be shared with other class members.
     However, that erroneous finding, alone, does not con-
 vince us that the administrative judge abused her discre-
 tion in denying class certification. Even if there were no
 privacy concerns implicating class formation, a conclusion
 that we do not need to reach, the administrative judge was
 justified in denying class certification based solely on her
 findings that the putative class would lack commonality
 and that identification of class membership would not be

    2     In finding that the administrative judge’s privacy
 concerns are unsupported, we do not go so far as to agree
 with Mr. Kluge that potential class members’ information
 could be kept entirely in the control of the government. See
 Pet’r’s Br. 26–27. We do not see how a class could be ade-
 quately represented by an attorney with no access to class
 members’ information. Potential class members’ military
 records and civilian pay records would have to be produced
 at least to class counsel if a class were certified.
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 10                                             KLUGE   v. DHS

 the fairest and most efficient way to proceed. See 5 C.F.R.
 § 1201.27(a).
     We do not go so far as to hold that class adjudication of
 claims for differential pay under 5 U.S.C. § 5538 will never
 be the fairest and most efficient way to proceed. We con-
 clude only that the administrative judge did not abuse her
 discretion in finding that the broad class proposed by Mr.
 Kluge may not be the fairest and most efficient way to pro-
 ceed as required by 5 C.F.R. § 1201.27(a).
                      B. Dismissal of OPM
     The administrative judge found that DHS, rather than
 OPM, was the proper party to respond to Mr. Kluge’s dif-
 ferential pay claim because DHS was Mr. Kluge’s employ-
 ing agency and had access to his employment records. J.A.
 6. Mr. Kluge asserts that the administrative judge erred
 in substituting DHS for OPM because he has a private
 right of action against OPM under 38 U.S.C. § 4324. Pet’r’s
 Br. 19–25. We review the statutory interpretation issues
 raised by Mr. Kluge de novo. See Butterbaugh v. Dep’t of
 Just., 336 F.3d 1332, 1336 (Fed. Cir. 2003). He argues that
 by dismissing OPM, the administrative judge denied him
 the opportunity to seek remediation of OPM’s allegedly in-
 correct guidance. Pet’r’s Br. 22, 24. We disagree.
     Section 4324 does not provide Mr. Kluge with a right of
 action against OPM in this case. Section 4324(b) provides,
 in relevant part, that a “person may submit a complaint
 against a Federal executive agency or the Office of Person-
 nel Management under this subchapter directly to the
 Merit Systems Protection Board.” The Board “shall adju-
 dicate any complaint brought before the Board pursuant to
 subsection . . . (b).” 38 U.S.C. § 4324(c)(1). And “[i]f the
 Board determines that a Federal executive agency or the
 Office of Personnel Management has not complied with the
 provisions of this chapter relating to the employment or
 reemployment of a person by the agency, the Board shall
 enter an order requiring the agency or Office to comply
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 KLUGE   v. DHS                                            11

 with such provisions and to compensate such person for
 any loss of wages or benefits suffered by such person by
 reason of such lack of compliance.” 38 U.S.C. § 4324(c)(2).
 But § 4324 does not, as Mr. Kluge implies, support an in-
 terpretation that a claimant may sustain a claim against
 OPM for differential pay that should be properly paid by a
 different agency. Congress separately identified OPM to
 indicate that a claimant can proceed against OPM “as an
 employer like any Federal agency” or “to assure the execu-
 tion of other OPM duties, for example, its duties on behalf
 of employees of the Federal Bureau of Investigation, the
 Central Intelligence Agency, and other agencies under sec-
 tion 4315(e).” S. Rep. No. 104-371, at 30–31 (1996). Mr.
 Kluge does not allege that he was employed by OPM and
 does not seek to assure the execution of any other OPM du-
 ties. J.A. 43–60. Rather, he seeks to recover differential
 pay that 5 U.S.C. § 5538(c)(1) indicates shall be paid by his
 “employing agency,” DHS. Section 4324 does not permit
 him to recover differential pay owed by DHS from OPM.
      Mr. Kluge argues that he must be permitted to main-
 tain an action against OPM to overturn OPM’s guidance,
 which states that “qualifying active duty does not include
 voluntary active duty under 10 U.S.C. [§] 12301(d).” Pet’r’s
 Br. 21–22; J.A. 495. He argues that DHS failed to pay his
 differential pay because it was following the OPM guidance
 and that he must be allowed to maintain a suit against
 OPM because its guidance was followed. Pet’r’s Br. 22. Mr.
 Kluge’s argument is misplaced, as the contested sentence
 of the guidance was not used to deny Mr. Kluge differential
 pay. See J.A. 464. Rather, DHS agreed with Mr. Kluge
 that he was owed differential pay. Id. Mr. Kluge asserts
 that he was constructively denied differential pay as it was
 not automatically provided to him but, rather, was only
 given to him after he asked for it in litigation approxi-
 mately ten years after his active duty. Pet’r’s Reply Br.
 13–18. But we cannot say here that DHS ever denied Mr.
 Kluge differential pay, constructively or otherwise. Mr.
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 12                                             KLUGE   v. DHS

 Kluge asserts, without any evidence, that DHS would have
 denied any request made prior to filing a lawsuit. Id. at 17.
 But he does not assert that he ever raised the issue with
 DHS before appealing to the Board. 3 Even more tenuous
 than Mr. Kluge’s assertion that DHS would have denied
 any request made outside of litigation is his assertion that
 the reason for that hypothetical denial would have been the
 OPM guidance. There are simply no plausible allegations
 that Mr. Kluge, or anyone else, was ever denied differential
 pay due to the OPM guidance.
     We conclude that Mr. Kluge has not shown any legal
 error or other abuse of discretion in the administrative
 judge’s substitution of DHS for OPM and dismissal of
 OPM.
                C. Differential Pay Calculation
     Finally, Mr. Kluge argues that the administrative
 judge erred in calculating the differential pay he is owed as
 $274.37 plus interest. Pet’r’s Br. 37–40; Pet’r’s Reply Br.
 26–30; see J.A. 20. He maintains that he is entitled to
 $17,166.30 plus interest. Pet’r’s Reply Br. 29; see J.A. 408
 (showing Mr. Kluge’s calculation). We disagree.

      3  We do not hold that it is proper for an agency to
 wait until it receives a request before paying differential
 pay. Indeed, 5 U.S.C. § 5538(c)(1)–(3) states that the em-
 ploying agency should pay differential pay “to the extent
 practicable, at the same time and in the same manner as
 would basic pay if such employee’s civilian employment
 had not been interrupted.” But, here, there is no indication
 that DHS’s failure to pay Mr. Kluge’s differential pay “at
 the same time and in the same manner as [it] would [pay]
 basic pay if such employee’s civilian employment had not
 been interrupted,” id. § 5538(c)(3), was due to the chal-
 lenged OPM guidance.
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 KLUGE   v. DHS                                           13

     Mr. Kluge and DHS agree to certain basic facts under-
 lying the differential-pay calculation, although they disa-
 gree as to the computation method. Both parties agreed
 that Mr. Kluge is entitled to a reservist differential under
 5 U.S.C. § 5538 for the period of February 27 to July 30,
 2011. J.A. 12; J.A. 464. They agree that Mr. Kluge re-
 ceived his civilian pay for the Fourth of July holiday but
 was otherwise on leave-without-pay status for this period.
 J.A. 12; J.A. 465; Pet’r’s Br. 10 n.8. They agree that, had
 he not been deployed, Mr. Kluge would have earned
 $4,704.80 per biweekly pay period, or $470.48 per eight-
 hour workday, in his civilian DHS job. J.A. 12; J.A. 464.
 Unlike his civilian pay, Mr. Kluge’s military pay was paid
 monthly. In February, the military paid him $11,630.74.
 J.A. 11. In each of March, April, May, and June, the mili-
 tary paid him $10,169.94. Id. In July, the military paid
 him $9,994.94. Id.
     OPM’s guidance provides a method for calculating dif-
 ferential pay, J.A. 483–88, but the administrative judge re-
 jected that method as unnecessarily complicated and
 unfair to military service members because it excludes hol-
 idays for which civilian employees are paid even though
 they do not have to work. J.A. 16. She developed her own
 calculation method for comparing bi-weekly civilian pay to
 monthly military pay on a pay-period basis. First, she con-
 verted monthly military pay to a bi-weekly equivalent by
 multiplying each month’s military pay by 12 to convert it
 to an annual amount, and then dividing by 26, the number
 of pay periods in pay year 2011. J.A. 17. She then con-
 verted the calculated bi-weekly military pay to a daily mil-
 itary pay amount by dividing by 10, the number of
 workdays in the civilian bi-weekly pay period. 4 Id. The

     4  Alternatively, the same calculation can be reached
 “by dividing the bi-weekly comparative pay by 80, the
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 14                                             KLUGE   v. DHS

 results of these conversions are summarized in the table
 below:

  Month         Monthly      Calculated   Calculated
                Military Pay Bi-Weekly    Daily
                             Military Pay Military Pay

  February      $11,630.74   $5,368.03       $536.80

  March         $10,169.94   $4,693.81       $469.38

  April         $10,169.94   $4,693.81       $469.38

  May           $10,169.94   $4,693.81       $469.38

  June          $10,169.94   $4,693.81       $469.38

  July          $9,994.94    $4,613.05       $461.30

 J.A. 16–20.
      The administrative judge used these calculated daily
 military pay rates to determine the pay Mr. Kluge received
 from the military during each bi-weekly civilian pay period,
 some of which extend across two months. For example, the
 first pay period at issue began on February 27, 2011, and
 ended on March 12, 2011. It included one civilian workday
 in February (February 28) and nine civilian workdays in
 March. J.A. 17–18. For that pay period, the administra-
 tive judge determined that Mr. Kluge’s military pay was a
 single day at the calculated daily military pay rate for Feb-
 ruary and nine days at the calculated daily military pay
 rate for March: ($536.80×1)+($469.38×9), yielding a total

 number of hours in a bi-weekly period, [and] the daily rate
 was calculated multiplying by 8, the number of hours in a
 workday.” J.A. 17.
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 KLUGE   v. DHS                                              15

 calculated military pay for that pay period of $4,761.23.
 J.A. 18. The results of the administrative judge’s calcula-
 tions are summarized below:

  Pay       Dates       Calculated    Civilian      Calculated
  Period                Military      Pay           Pay
                        Pay                         Differential

  5         2/27–3/12   $4,761.23     $4,704.80     None

  6         3/13–3/26   $4,693.81     $4,704.80     $10.99

  7         3/27–4/9    $4,693.81     $4,704.80     $10.99

  8         4/10–4/23   $4,693.81     $4,704.80     $10.99

  9         4/24–5/7    $4,693.81     $4,704.80     $10.99

  10        5/8–5/21    $4,693.81     $4,704.80     $10.99

  11        5/22–6/4    $4,693.81     $4,704.80     $10.99

  12        6/5–6/18    $4,693.81     $4,704.80     $10.99

  13        6/19–7/2    $4,684.73     $4,704.80     $20.07
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 16                                                KLUGE   v. DHS

  Pay      Dates        Calculated    Civilian      Calculated
  Period                Military      Pay           Pay
                        Pay                         Differential

  14       7/3–7/16     $4,151.70     $4,237.02     $85.62 6
                                      5

  15       7/17–7/30    $4,613.05     $4,704.80     $91.75

 J.A. 16–20. The administrative judge concluded that Mr.
 Kluge was owed differential pay totaling $274.37 plus in-
 terest. J.A. 20.

       5  Mr. Kluge’s civilian pay is lower for pay period 14
 because DHS paid him $470.48 for the Fourth of July fed-
 eral holiday. J.A. 20. We note that there appears to be an
 error of approximately three dollars in the administrative
 judge’s calculation of the civilian pay Mr. Kluge would have
 earned during this pay period but for his military service.
 We calculate that Mr. Kluge would have received $4,234.32
 in civilian pay for that pay period, calculated by subtract-
 ing his $470.48 holiday pay from his $4,704.80 civilian bi-
 weekly pay. The administrative judge calculated that he
 would have received $4,237.02. As this error is in Mr.
 Kluge’s favor and the government does not appeal the ad-
 ministrative judge’s calculation, we will not find that Mr.
 Kluge’s differential pay award should be decreased.
     6    There also appears to be an error of 30 cents in the
 administrative judge’s calculation of differential pay for
 pay period 14. While the administrative judge calculated
 that Mr. Kluge was entitled to $85.62 in differential pay, if
 we assume that his civilian biweekly pay would have been
 $4,237.02, then he was entitled to $85.32 in differential
 pay. As this error is also in Mr. Kluge’s favor, we will not
 find that the amount of differential pay awarded to him
 should be decreased.
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 KLUGE   v. DHS                                            17

      Mr. Kluge disagrees. He asserts that he is owed
 $17,166.30 plus interest or, in the alternative, three times
 that amount. Pet’r’s Br. 37–39; Pet’r’s Reply Br. 29. He
 argues that the administrative judge failed to consider the
 different number of workdays that he was expected to work
 while on active duty in the military versus at a civilian job
 and that a military job requires 24-hour accountability.
 Pet’r’s Br. 37–39. To account for the fact that a reservist
 on active duty is expected to work seven days a week (four-
 teen days over a two-week period), while they would only
 work five days at their civilian job (ten days over a two-
 week period), Mr. Kluge would calculate his daily military
 pay rate by dividing his monthly military pay by the num-
 ber of days in that month. J.A. 407. Thus, for March, Mr.
 Kluge would find that he was paid $328.06 7 per day
 ($10,169.94 divided by 31, the number of days in March),
 rather than $469.38 as the administrative judge found.
 Compare J.A. 18, with J.A. 407–08. By calculating daily
 military pay in this manner, Mr. Kluge divides his monthly
 military pay over all days, including weekends and holi-
 days, equally. He then calculates differential pay by com-
 paring the military pay accrued only for the days he would
 have been working in his civilian employment to the total
 civilian pay he would have received had he not been on ac-
 tive duty. J.A. 408. For the first time on appeal, he goes
 even further, arguing that differential pay should be calcu-
 lated on an hourly basis rather than a daily basis to

     7   We note that Mr. Kluge’s calculations, provided on
 J.A. 408, include some mathematical errors. For example,
 Mr. Kluge’s calculation appears to use the incorrect num-
 ber of days for the month of February and includes differ-
 ential pay for the period from July 31 to August 12, even
 though his active-duty service ended on July 30. See J.A.
 408; J.A. 225. Throughout this opinion, when we describe
 the calculation Mr. Kluge proposes, we attempt to follow
 the method he describes without reproducing the errors.
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 18                                                 KLUGE   v. DHS

 account for the fact that while on active duty he was ac-
 countable to his commander at all hours—effectively a 24-
 hour workday. Pet’r’s Br. 39. He therefore asks, in the
 alternative, for his differential pay calculation ($17,166.30
 plus interest) to be multiplied by three to account for the
 disparity between the 24-hour military workday and the 8-
 hour civilian workday. Id.
      We may set aside the administrative judge’s differen-
 tial pay calculation only if it is “(1) arbitrary, capricious, an
 abuse of discretion, or otherwise not in accordance with
 law; (2) obtained without procedures required by law, rule,
 or regulation having been followed; or (3) unsupported by
 substantial evidence.” 5 U.S.C. § 7703(c). The issue here
 is whether the administrative judge’s calculation method
 complies with the statute governing differential pay, 5
 U.S.C. § 5538.
     We find Mr. Kluge’s arguments regarding the calcula-
 tion of differential pay unpersuasive because his proposed
 method is contrary to 5 U.S.C. § 5538. Section 5538 pro-
 vides that:
      (a) An employee who is absent from a position of
      employment with the Federal Government in order
      to perform active duty in the uniformed services
      pursuant to a call or order to active duty under sec-
      tion 12304b of title 10 or a provision of law referred
      to in section 101(a)(13)(B) of title 10 shall be enti-
      tled, while serving on active duty, to receive, for
      each pay period described in subsection (b), an
      amount equal to the amount by which--
          (1) the amount of basic pay which would
          otherwise have been payable to such em-
          ployee for such pay period if such em-
          ployee’s civilian employment with the
          Government had not been interrupted by
          that service, exceeds (if at all)
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 KLUGE   v. DHS                                            19

          (2) the amount of pay and allowances
          which (as determined under subsection
          (d))--
              (A) is payable to such employee for
              that service; and
              (B) is allocable to such pay period.
 5 U.S.C. § 5538 (emphases added). The statute specifies
 that differential pay should be calculated by determining
 the difference between civilian pay for a pay period and the
 military pay allocable to that pay period. Mr. Kluge asks
 for differential pay to be calculated on a per day (or per
 hour) basis rather than on the per pay period basis re-
 quired by the statute.
      We also reject Mr. Kluge’s argument that the adminis-
 trative judge’s differential pay calculation is contrary to
 our decision in Butterbaugh. Pet’r’s Br. 37–40. In Butter-
 baugh, we addressed a different statute, 5 U.S.C.
 § 6323(a)(1), under which federal employees are granted up
 to “15 days” of paid leave to attend reserve or National
 Guard training. 336 F.3d at 1333. We held that federal
 agencies’ practice of counting every day of training, includ-
 ing weekends and holidays, against their employees’ allot-
 ted military leave violated the statute. We held that “the
 ‘days’ that section 6323(a)(1) refers to are leave days, not
 ‘training days’ or ‘reserve duty days.’” Id. at 1337. We ex-
 plained that, generally, “employees are not accountable to
 their employers for time they are not required to work,”
 and federal employees did not need to expend their military
 leave for days on which they were not scheduled to work
 for their federal agency employer. Id. Butterbaugh does
 not help Mr. Kluge because § 5538, unlike § 6323(a)(1),
 specifies that differential pay should be calculated and paid
 on a per pay period basis, not on a per day basis. Butter-
 baugh’s analysis of the word “day” in § 6323(a)(1) is simply
 irrelevant to the differential pay calculation under § 5538.
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 20                                             KLUGE   v. DHS

      We do not hold that the administrative judge’s calcula-
 tion method is the best or only way to calculate differential
 pay under § 5538. We only hold that Mr. Kluge has failed
 to show that the administrative judge violated § 5538 or
 otherwise abused her discretion in calculating the differen-
 tial pay owed in this case.
                       III.    CONCLUSION
     We have considered Mr. Kluge’s other arguments and
 find them unavailing. For the foregoing reasons, we affirm
 the Board’s final decision.
                        AFFIRMED
                              COSTS
 No costs.