Convert calendar constants to enums and add months #103636

From this discuss thread:

The calendar module already defines constants e.g. MONDAY (0), TUESDAY (1), etc. for the [days of the week] https://docs.python.org/3/library/calendar.html#calendar.MONDAY).

Since these are likely to be commonly needed too, would it make sense for the calendar module to also export constants for all of JANUARY (1), FEBRUARY (2), …, DECEMBER (12)?

This would allow one to write from calendar import APRIL and then e.g. use APRIL instead of 4 when building a datetime.date object.

Related: datetime - Python module defining constants for month numbers? - Stack Overflow

Linked PRs

• gh-103636: add enums for days and months in calendar module #103642
• gh-103636: issue warning for deprecated calendar constants #103833