D.C. Mun. Regs. tit. 6, r. 6-B1238
Pursuant to section 1238.3 of this section, annual leave that is not used by an employee shall accumulate for use in succeeding years, except that annual leave in excess of two hundred forty (240) hours at the beginning of the first full biweekly pay period of the calendar year, or the corresponding period for an employee who is not paid on the basis of biweekly pay periods, shall be forfeited as provided in section 1238.2 of this section.
The beginning of the first biweekly pay period in the calendar year shall be the point at which an employee's accumulated annual leave balance is fixed, and when a determination shall be made that annual leave in excess of the maximum amount allowable under section 1238.1 of this section, as appropriate, shall be forfeited.
Annual leave in excess of the amount allowable under this section that was accumulated under an earlier statute shall remain to the credit of the employee until used. If an employee with such credit uses more annual leave in a leave year than he or she earns:
D.C. Mun. Regs. tit. 6, r. 6-B1238