Return newly added Enum constants for month and days in calendar module

[Agent-Hellboy]

Pitch

As discussed with @ethanfurman in one of my PR, I am going to create a PR to change the return type of functions and methods which currently return ints from 0-7 and 1-12 to represent days and months to newly added enum attributes

Previous discussion

the previous discussion can be tracked from the last comment on #103642

Linked PRs

• gh-103822: change return value to enum for day and month APIs #103827

[hauntsaninja]

Thanks!