Recurring payments - how long is a month?

Question

For monthly recurring payments, how long is a month defined to be? I need to be able to independently track subscription end dates on my web service and I'd like to be consistent with PayPal.

Answer 1

As said on PayPal's documentation:

How Subscriptions with Monthly Billing Cycles Work

For monthly billing cycles, recurring payments are collected on the same day of the month. If the initial recurring payment falls on the 31st, PayPal eventually adjusts the billing cycle to the 1st of the month. If the initial recurring payment falls on the 29th or 30th, PayPal adjusts the billing cycle to the 1st of the month on the following February.

When Monthly Recurring Payments Are Due and Collected on the 31st

The subscription terms are:

$25.99 USD a month; the subscriber signs up on Thursday, July 31. The subscriber is billed as follows:

Thursday, July 31 = $25.99 USD Saturday, August 31 = $25.99 USD Wednesday, October 1= $25.99 USD Saturday, November 1= $25.99 USD and so on... Notice that no recurring monthly payment was collected in September, but recurring payments were collected roughly every 30 days.

When Monthly Recurring Payments Are Due and Collected on the 30th

The subscription terms are:

$25.99 USD a month; the subscriber signs up on Tuesday, December 30. The subscriber is billed as follows:

Tuesday, December 30 = $25.99 USD Friday, January 30 = $25.99 USD Sunday, March 1= $25.99 USD Wednesday, April 1= $25.99USD and so on... Notice that no recurring monthly payment was collected in February, but recurring payments were collected roughly every 30 days.

Read more at https://developer.paypal.com/webapps/developer/docs/classic/paypal-payments-standard/integration-guide/subscribe_buttons/