(b) For the purpose of readily determining the amount of rentals chargeable against tenants moving into a dwelling unit, where the effective date of tenancy is other than the first day of the month, or against tenants vacating a dwelling unit where the charge-through date is other than the last day of the month, the local agency shall establish pro rata rent schedules for 28-, 29-, 30-, and 31-day months covering each anticipated basic rent charge in the dwelling rent schedule. Similar pro rata rent schedules should be established, where possible, for each anticipated rent surcharge. Where such is not possible, the rent surcharge for a fractional part of a month shall be computed on the same principles as are employed in constructing a pro rata schedule. In preparing a pro rata rent schedule, a daily rental rate is first determined by dividing the monthly rental charge by the number of days in the month, carrying the figure out to five decimal places. The proportionate rental for a fractional part of a month is then determined by multiplying the daily rental rate by the number of days in the fraction. A specimen pro rata rent schedule for a 30-day month follows:

Pro Rata Rent Schedule for Fractional Parts of a 30-day Month