Apple, unlike other app stores, uses a custom payment calendar where months don't start on the 1st and don't end end 30/31 days later. Instead of using standard calendar months, Apple set up its own fiscal calendar and uses it to pay developers.

The Payments Report automatically uses this calendar to report estimated and actual payments.

For the latest calendar, click here

Here's the calendar for 2022:

In case you're curious how this calendar works:

1. Every month starts on a Sunday and ends on a Saturday.
2. The first quarter starts at the end of September.
3. Every quarter starts with a 5-week month, followed by two 4-week months.
4. Every 5th or 6th year, depending on Apple, an extra week is added to Q1. The next year to have the additional week is 2023.

And, Apple usually pays 33 days after the end of the fiscal month.

View Apple's version, in App Store Connect (login required)