5 CFR § 551.521
Fractional hours of work
November 4, 2020
(a) An employee shall be compensated for every minute of regular overtime work.
(b) A quarter of an hour shall be the largest fraction of an hour used for crediting irregular or occasional overtime work under this subpart. When irregular or occasional overtime work is performed in other than the full fraction, odd minutes shall be rounded up or rounded down to the nearest full fraction of an hour used to credit overtime work.
[48 FR 36806, Aug. 15, 1983]