DoL regulation 29 C.F.R. §553.25 reads:

(a) Section 7(o)(5) of the FLSA provides that any employee of

a public agency who has accrued compensatory time and

requested use of this compensatory time, shall be permitted to use

such time off within a “reasonable period” after making the

request, if such use does not “unduly disrupt” the operations of

the agency. This provision, however, does not apply to “other

compensatory time” (as defined below in § 553.28), including

compensatory time accrued for overtime worked prior to April

15, 1986.

(b) Compensatory time cannot be used as a means to avoid statutory

overtime compensation. An employee has the right to use

compensatory time earned and must not be coerced to accept

more compensatory time than an employer can realistically and

in good faith expect to be able to grant within a reasonable period

of his or her making a request for use of such time.

(c) Reasonable Period.

(1) Whether a request to use compensatory time has been granted

within a “reasonable period” will be determined by considering

the customary work practices within the agency based on the

facts and circumstances in each case. Such practices include, but

are not limited to (a) the normal schedule of work, (b) anticipated

peak workloads based on past experience, (c) emergency requirements

for staff and services, and (d) the availability of qualified

substitute staff.

(2) The use of compensatory time in lieu of cash payment for

overtime must be pursuant to some form of agreement or under-

standing between the employer and the employee (or the repre-

sentative of the employee) reached prior to the performance of

the work. (See § 553.23.) To the extent that the conditions under

which an employee can take compensatory time off are contained

in an agreement or understanding as defined in § 553.23, the

terms of such agreement or understanding will govern the meaning

of “reasonable period.”

(d) Unduly Disrupt. When an employer receives a request for

compensatory time off, it shall be honored unless to do so would

be “unduly disruptive” to the agency’s operations. Mere inconvenience

to the employer is an insufficient basis for denial of a

request for compensatory time off. (See H. Rep. 99-331, p. 23.)

For an agency to turn down a request from an employee for compensatory

time off requires that it should reasonably and in good

faith anticipate that it would impose an unreasonable burden on

the agency’s ability to provide services of acceptable quality and

quantity for the public during the time requested without the use

of the employee’s services.

Wage and Hour Division Opinion Letter, 1994 WL 1004861,
dated Aug. 19, 1994, states in relevant part:

“It is our position, notwithstanding the [Agreement], that an

agency may not turn down a request from an employee for compensatory

time off unless it would impose an unreasonable burden

on the agency’s ability to provide services of acceptable

quality and quantity for the public during the time requested

without the use of the employee’s services. The fact that overtime

may be required of one employee to permit another employee to

use compensatory time off would not be a sufficient reason for

an employer to claim that the compensatory time off request is

unduly disruptive.”