Fix parsing timestamps with zone 'Z'

[minus7]

Since timestamps are defined to be ISO 8601, parsing a 'Z' as timezone
offset should be supported. For compatibility, generating of timestamps is untouched, i.e. still generates zone offsets '+00:00'.

[codecov]

Codecov Report

Merging #17 (25cfcd3) into main (74420ed) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main      #17   +/-   ##
=========================================
  Coverage     83.10%   83.10%           
  Complexity      251      251           
=========================================
  Files            54       54           
  Lines           734      734           
  Branches         53       53           
=========================================
  Hits            610      610           
  Misses           94       94           
  Partials         30       30           

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[bdemers]

Thanks @minus7 ! I just pushed a commit: 25cfcd3 to format date strings to use the id as well. IMHO, it's easier to keep things consistent.
Thoughts?

[minus7]

I first had it like that as well, but then kept the '+00:00' to avoid breaking people's broken ISO8601 parsers. On the other hand, that's not really a bad thing. LGTM

[bdemers]

Thanks @minus7 !!