Seven police officers and other unnamed plaintiffs (“Plaintiffs”) currently or formerly employed by the Woodbury County Sheriffs Department (the “Sheriffs Department”) filed suit against Woodbury County (the “County”) for its alleged failure to pay overtime compensation in violation of the Fair Labor Standards Act (“FLSA”), 29 U.S.C. §§ 201-19. A jury returned a verdict in favor of the County on all issues and claims. Plaintiffs appeal, claiming that the district court 1 erred by failing to grant their motion for summary judgment, by failing to grant their motion for judgment as a matter of law, and by issuing and refusing to issue certain jury *778 instructions. Having jurisdiction under 28 U.S.C. § 1291, we affirm.
I.
Plaintiffs filed suit against the County, alleging that it had failed to pay them overtime compensation in violation of the FLSA. Specifically, Plaintiffs raise three distinct pay-related claims. Plaintiffs Jim Cunningham and Charles Hertz allege that the County failed to compensate them for work performed during their commute time. Plaintiffs Cunningham, Todd Wieck, the Estate of David Fox, Michael Tadlock, Scott Lanagan, and Rebecca Legore-Post claim that the County failed to compensate them for work performed during Plaintiffs’ mealtimes. Plaintiffs Cunningham, Hertz, Wieck, Tadlock, and Lanagan allege unpaid compensation for general overtime.
During the time relevant to this case, the named Plaintiffs occupied a number of varied positions in the Sheriffs Department. Sergeant Cunningham has been employed at the Sheriffs Department since June 1980. He is in charge of investigations, crime prevention, the school-resource program, and the Drug Abuse Resistance Education (“DARE”) program. Cunningham’s scheduled work hours are from 8:00 a.m. until 4:30 p.m. with a half-hour lunch break. He is required to start and end the day at his desk with administrative duties. Lieutenant Hertz has been employed at the Sheriffs Department since May 1978. He is in charge of all of the patrol shifts, the hostage-rescue team, the K-9 division, and investigations and crime prevention. His scheduled hours are from 8:00 a.m. to 4:00 p.m. with no lunch break. He is also required to start and end his work day at his desk with administrative duties. Cunningham reports directly to Hertz.
Sergeant Wieck has been employed by the Sheriffs Department since July 1990 as a DARE officer, a school-resource officer, and a community-policing, officer. He works from 8:00 a.m. until 4:30 p.m. with a half-hour lunch break. Lanagan has been an employee of the Sheriffs Department since May 1987. As a crime-scene investigator, his scheduled work hours are from 7:00 a.m. until 3:30 p.m.; however, during the summer he works from 8:00 a.m. until 4:30 p.m. He has a half-hour lunch break. Former Sergeant Tadlock worked at the Sheriffs Department from April 1977 until June 2004. He was most recently in charge of the crime-prevention division and worked from 8:00 a.m. until 4:30' p.m. with a half-hour lunch break. Former Sergeant Legore-Post was employed at the Sheriffs Department from May 1985 until February 2006 as a court-security officer. Her scheduled hours were from 8:00 a.m. until 4:30 p.m. with a half-hour lunch break. Fox was employed by the Sheriffs Department from February 1981 until his death. At the time of his death, he worked in the day-patrol division from 8:00 a.m. until 4:30 p.m. with a half-hour lunch break. The timing of the officers’ lunch breaks was at their discretion.
Woodbury County is 960 square miles, encompassing Sioux City and several largely rural communities. Many of the Plaintiffs testified that they live many miles from the police station and have lengthy commutes each morning. The County provides all of its officers with marked police vehicles that it authorizes them to drive to and from their residences each day. It has been the County’s practice to keep track of officers’ actions by having, them report their availability through a series of codes. The code “10-41” signifies that an officer has begun his or her tour of duty and is prepared to answer calls for assistance, including requests to help motorists, investigate accidents, and direct traffic. Conversely, the *779 code “10-42” signals that an officer has completed his or her tour of duty and is no longer available to respond for police business. It is undisputed that the County’s policy requires officers to go “10-41” at their residences at the beginning of each work day. Once an officer has returned to his or her residence at the end of a shift, the officer is able to go “10-42.” The County tracks the duty-status of an officer through a program known as Computer Aided Dispatch (“CAD”). CAD records the moment that an officer goes “10-41” in the morning and the moment at which each officer goes “10-42” in the evening. It is also used throughout the day if an officer is unavailable for any reason. In addition to allowing the officers to engage in law-enforcement activity while they drive, by allowing the officers to use patrol cars as commute vehicles, the County hopes to diminish response time to requests for assistance and generally increase police presence in the jurisdiction.
The FLSA requires the County to keep track of the working hours of each employee that falls under the Act. 29 C.F.R. § 516.2. The County does this through a “sign-in sheet.” Under this system, each officer is required to initial a sheet to indicate that the officer has worked his or her scheduled hours that day. In addition to this sheet, the payroll office uses overtime slips and vacation logs to compute each officer’s time worked. When officers work overtime, they must submit an overtime slip to their supervisors indicating the amount of time worked in excess of their scheduled hours. The supervisors are then responsible for approving the overtime, and the slip is co-signed by either the division head or the chief deputy. After obtaining the proper signatures, the slip is forwarded to the payroll office and paid at the rate of one-and-a-half times the rate of pay. A former chief deputy testified that these overtime requests were “rarely denied.”
Plaintiffs moved for summary judgment arguing that there were no material facts in dispute as to whether the County owed the Plaintiffs wages for unpaid commute time, mealtime, and general overtime. Within that motion, the Plaintiffs also argued for judgment as a matter of law under Federal Rule of Civil Procedure 50(a). See Fed.R.Civ.P. 50(a). The district court denied summary judgment and judgment as a matter of law. At the close of the evidence, the Plaintiffs renewed their motion for judgment as a matter of law under Rule 50(a), which the district court again denied. The district court then submitted the case to the jury. The jury returned a verdict in favor of the County on all claims, and the district court entered the final judgment against the Plaintiffs on June 20, 2008. Plaintiffs failed to renew their motion for judgment as a matter of law under Federal Rule of Civil Procedure 50(b) within ten days of the entry of judgment. See Fed.R.Civ.P. 50(b). The Plaintiffs appeal the district court’s denial of their motion for summary judgment, its denial of their 50(a) motion for judgment as a matter of law, and its issuance and refusal to issue certain jury instructions.
II.
Plaintiffs first argue that the district court erred in denying their motion for summary judgment. This court, however, “will not review a district court’s denial of a motion for summary judgment after a trial on the merits.”
EEOC v. Sw. Bell Tel., L.P.,
As Plaintiffs note, we have, in at least one instance, allowed a party to appeal a district court’s denial of summary judgment after final judgment when there were no disputed material facts and “the denial of summary judgment [was] based on the interpretation of a purely legal question.”
See id.
at 1190 (allowing an appeal of a denial of summary judgment in a contracts case because “interpretation of a contract is a question of law for the court to decide”) (quotation omitted). But in arguing that this case comes within any such limited exception for “purely legal questions,” Plaintiffs mischaracterize their claims. At the time of the motion, the issues were not purely legal; rather, there were numerous and varied questions of material fact with regard to the compensability of commute-time, mealtime, and other overtime claims.
Cf. Skidmore v. Swift & Co.,
III.
Plaintiffs further allege that the district court erred in denying their motion for judgment as a matter of law with respect to the drive-time, mealtime, and other overtime compensation claims.
See
Fed.R.Civ.P. 50(a). This court reviews a “denial of a motion for judgment as a matter of law de novo.”
Heaton v. The Weitz Co.,
Both parties cite
Cross v. Cleaver
for the proposition that absent a Rule 50(b) -motion, this court reviews the district court’s denial of a motion for judgment as a matter of law for plain error.
See Cross v. Cleaver,
IV.
Finally, Plaintiffs claim that the district court erred in issuing and failing to issue various instructions to the jury. “When reviewing ... jury instructions for error, we must consider the instructions in their entirety. Jury instructions are generally committed to the sound discretion of the district judge, and the district judge is entitled to a great deal of deference in his or her formulation.... Moreover, a single erroneous instruction does not require reversal if the charge as a whole fairly and adequately submits the issue to the jury.”
May v. Ark. Forestry Comm’n,
A. No Duty to Examine CAD Logs for Payroll Purposes
Plaintiffs claim that the district court erred in instructing the jury from the bench that the County had no legal duty to consult the CAD logs for payroll purposes. They argue that such an instruction precluded them from establishing that the County knew or should have known that they were working overtime.
An employee must be compensated for duties “before and after scheduled hours ... if the employer knows or has reason to believe the employee is continuing to work and the duties are an integral and indispensable part of the employee’s principal work activity.”
Mumbower v. Callicott,
Because constructive knowledge of overtime work is sufficient to establish liability under the FLSA, if the County, through reasonable diligence, should have acquired knowledge that Plaintiffs were working in excess of their scheduled hours, the jury would have been empowered to find th,e County liable.
See Stewart,
Testimony at trial indicated that while County officials, including the Sheriffs Department payroll office, technically had access to the CAD records, they were not used for payroll purposes. As the County bookkeeper and the County Sheriff testified, the. CAD records are only used so that dispatchers know what officers are available to respond to an emergency. They essentially amount to a daily report of officer activity and only are referenced to gain an overview of what types of emergencies occurred during a particular period, as opposed to the schedules of particular officers.
The FLSA’s standard for constructive knowledge in the overtime context is whether the County “should have known,” not whether it could have known.
See. Stewart,
121 ,F-3d at 407. It would not be reasonable to require that the County weed through non-payroll CAD records to determine whether or not its employees were' working beyond their scheduled hours. This is particularly true given the fact that the County has an established procedure for overtime claims that Plaintiffs regularly used.
See Newton,
This case is distinguishable from other instances where courts have found constructive knowledge based on an employer’s access to non-payroll records. There is no indication here that the officers were discouraged from submitting overtime slips or that submitted slips went unpaid.
See Brennan v. Gen. Motors Acceptance Corp.,
We' do not foreclose the possibility that another case may lend itself to a finding that access to records would provide constructive knowledge of unpaid overtime work. And, in such a case, an instruction similar to that which the district court gave may be erroneous. Given the particular circumstances here, however, the district court correctly determined that the CAD logs could not serve as a basis upon which to find that the County had constructive knowledge of unpaid overtime. To permit such an instruction would require that the County engage in actions beyond the “reasonable diligence” the law requires of employers when determining whether their employees are working overtime.
See Stewart,
*783 B. Burden of Proof As to Mealtime Compensation
Plaintiffs also appeal the district court’s instruction that assigned Plaintiffs the burden of proof to show that they were engaged in conduct “primarily for the benefit of the employer” and that their mealtimes were thus compensable.
See Henson v. Pulaski County Sheriff Dept.,
The Supreme Court has indicated that the “general rule [is] that the application of an exemption under the Fair Labor Standards Act is a matter of affirmative defense on which the employer has the burden of proof.”
Corning Glass Works v. Brennan,
In essence, a claim for unpaid mealtime work is no different than other overtime claims where it is the plaintiffs burden to show (1) that the plaintiff has performed compensable work and (2) the number of hours for which the plaintiff has not been properly paid.
Cf. Goldberg v. Kickapoo Prairie Broad. Co.,
Plaintiffs cite Fourth and Fifth Circuit case law as support for the proposition
*784
that the County bears the burden because mealtimes qualify as an “exemption” within the meaning of the FLSA.
See Roy v. County of Lexington,
In conclusion, we believe that under the FLSA, the employee bears the burden to show that his or her mealtimes were compensable work. The district court thus did not err in its jury instruction.
C. Miscellaneous Jury Instructions
Plaintiffs further argue that the district court erred in refusing to give jury instructions that highlighted the County’s duty to ensure that the officers refrained from performing overtime work and that the County had an obligation to keep records of the time its employees worked. We disagree. Provided that the “charge as a whole fairly and adequately submits the issue to the jury,” we will find no reversible error.
See May,
V.
For the foregoing reasons, we affirm the decision of the district court.
Notes
. The Honorable Donald E. O'Brien, United States District Judge for the Northern District of Iowa.
. Notably, the district court did not preclude Plaintiffs from discussing the CAD logs for *783 other relevant issues, such as proving when Plaintiffs arrived and left work. The court’s statement to the jury was as follows: “Wood-bury County has no legal obligation to consult CAD logs in conjunction with the processing of payroll for its employees, and that was testified to by [the bookkeeper] and others [and] there’ll be no more questions about CAD logs in conjunction with payroll.”
