Normal Days
As mentioned previously, the rate schedule references a frequency that specifies the number of times per year that service agreements referencing the rate are expected to bill. The following formula dictates a rate frequency's normal days: 365 days / number of periods per year.
Example:
• For a monthly frequency (12 periods per year), 365 / 12 = 30 days.
• For a quarterly frequency (4 periods per year), 365 / 4 = 91 days.
Fastpath: 
Refer to Defining Frequency Codes for more information.