20 CFR § 322.5 - Payments under vacation agreements.
(a) General. In ascertaining the accrual of remuneration under a vacation agreement, consideration shall be given to the applicable agreements and practices, the interpretations of such agreements and practices developed by the parties, and the actions of the parties pursuant thereto. When there is information that an employee has received or is to receive payment under a vacation agreement, such payment shall, in the absence of evidence to the contrary, be considered to be remuneration with respect to the days to which the payment is assigned.
(b) Vacation pay. If an employee takes a vacation in accordance with a vacation agreement, the payment for such vacation shall constitute remuneration with respect to the days in the vacation period for which the payment is made. An employee shall be regarded as taking a vacation when, in accordance with the applicable agreements and practices (1) he is absent from work during a scheduled or assigned vacation period; (2) he is required to take his vacation with pay while he is on furlough; or (3) he chooses to take his vacation with pay while he is unemployed or absent from work due to illness or other personal circumstances.
(c) Pay in lieu of vacation. If a payment in lieu of vacation is made to an employee under a vacation agreement such payment shall not constitute remuneration with respect to any particular day or days. A payment under a vacation agreement shall be regarded as in lieu of vacation if:
(1) The payment is made at the end of the vacation year to an employee who did not take his vacation during such year; or
(2) The payment is made after the employee's death, or after he ceased service for the purpose of receiving an annuity, and the payment is credited to the employee's last day of service; or
(3) It is otherwise established that the parties intended the payment to be in lieu of vacation, without reference to any particular period.