[Question] Can remove `dateutil` from dependency?

[isac322]

Feature Request

Python 3.9 introduced ZoneInfo and it backported 3.6+ (https://pypi.org/project/backports.zoneinfo/).
Looking at the code, except for dateutil.rrule and dateutil.relativedelta, it seems that dateutil is being used for some reason related to timezone. Can ZoneInfo replace the part and delete dateutil?

[anishnya]

@jadchaar, @krisfremen and @systemcatch are more well-versed on this than I am. From what I recall, there was talk about removing dateutil as dependency earlier last year.

[jadchaar]

Yup, it would be great to lose a dependency wit ZoneInfo, but we'd need to port over rrule and relativedelta or find potential alternatives before dropping the library. A PR would be appreciate @isac322 :)!

[jadchaar]

Related to:
#825
#825