datetime

Describe the enhancement
While using the UpdateLocale Plugin, it isn't possible to just update one single value in a nested value.
For example I just want to update the format.L value:

dayjs.extend(UpdateLocale);
dayjs.updateLocale('de', {
  formats: {
    L: 'D.M.YYYY',
  },
});

Like this other formats LL, LLL, ... are getting lost.

Expected behavior
I want

Issue Description

I think we should improve the doc strings in parser.py to be more descriptive and similar like the rest of Arrow.

I'd like an /Examples folder with some simple iOS apps showing how to use Time.

The first one that comes to mind is a basic iOS app using a UICollectionView to build a month calendar view.

This is related to #410 and #859, we currently only support a limited subset of possible values for RDATE, but we should support all the parameters in RDATE, the grammar for which is set out in RFC 5545:

       rdate      = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF

       rdtparam   = *(
                  ;
                  ; T