For the purposes of this chapter, the term "payroll period" means the period for which a payment of wages is ordinarily made to the employee by an employer.
It is immaterial that the wages are not always paid at regular intervals. The following are examples of this situation:
An employee can have one (1) payroll period with respect to wages paid by any one (1) employer. Thus, if an employee is paid a regular wage for a weekly payroll period and, in addition, is paid supplemental wages (for example, a bonus) which is determined with respect to a different period, the payroll period is the weekly payroll period.
The term "miscellaneous payroll period," as used in this chapter, means a payroll period other than a daily weekly, biweekly, monthly, semi-monthly, quarterly, semi-annual, or annual payroll period.
If wages are paid for a period which is not a payroll period, the amount to be deducted and withheld shall be the amount applicable in the case of a miscellaneous payroll period containing a number of days (including Sundays and holidays) equal to the number of days in the period with respect to which the wages are paid.
If wages are paid without regard to any period (for example, the commission paid to a salesman upon consummation of a sale), the amount of tax to be deducted and withheld shall be determined in the same manner as in the case of a miscellaneous payroll period containing the number of days (including Sundays and holidays) which have elapsed since the date of the last payment of wages by the employer during the calendar year or the date of commencement of employment during that year, or January 1st of that year, whichever is the latest.
If wages are paid to an employee for a payroll period of more than one (1) year, the amount of the tax required to be deducted and withheld with respect to those wages shall be determined as if the payroll period constituted a miscellaneous payroll period of three hundred and sixty-five (365) days.
D.C. Mun. Regs. tit. 9, r. 9-137