Proration is a billing concept that is applicable to Subscription Products. Subscription product pricing is based on a fixed time e.g., per day or per month or per year etc.

Proration is applied when a change occurs mid-period to determine the amount to charge for the partial period.

MonetizeNow supports two proration types:

  • Day-Based
  • Month-Based

Video walkthrough of the two models


In the Day-Based proration method, we use the number of days as the way to calculate proration. More specifically, the proration is decided based on the number of days between the end date and the start date.

Let's understand this concept by using an example.

Let's say the price of a Product is $120/year

We need to determine the price of this product for a period of 6 months, with the following dates.
Start date = Feb 15, 2023
End date = Aug 14, 2023

Here's how Day Based Proration will work in this case:

  • Day-based proration = Days between (Aug 14 - Feb 15) = 180
  • Total days in a year starting on Feb 15, 2023 = 365
  • Proration = 180 / 365
  • Price = $120 * 180 / 365 = $59.18


Leap-year consideration

The denominator in the above equation will be 366 in leap years.


Treats each month the same, no matter how many days there are in the month and all fractional calculations are applied to the final month of the calculation.

  • Count the number of months starting from the start date
  • For the last month use fractional days, if any remaining

For example:

  • 6
  • 0

Proration = 6
Price = $120 / 12 * 6 = $60