D.C. Code § 32-1302
An employer shall pay all wages earned to his or her employees on regular paydays designated in advance by the employer and at least twice during each calendar month; except, that all bona fide administrative, executive, and professional employees (those employees employed in a bona fide administrative, executive, or professional capacity, as defined in section 7-999.1 of the District of Columbia Municipal Regulation (7 DCMR § 999.1)) shall be paid at least once per month; provided, however, that an interval of not more than 10 working days may elapse between the end of the pay period covered and the regular payday designated by the employer, except where a different period is specified in a collective agreement between an employer and a bona fide labor organization; provided further, that where, by contract or custom, an employer has paid wages at least once each calendar month, he may lawfully continue to do so. Wages shall be paid on designated paydays in lawful money of the United States, or checks on banks payable upon demand by the bank upon which drawn.
D.C. Code § 32-1302