Support for weekyear

[flomedja]

Description

There is no option for the week year representation as in this library .
This package is used by openTelemetry for parsing logstash_format date and in some edge case the weekyear is different from the year. It will be helpful to support the weekyear to update the package in openTelemetry.

I propose to add the options :

• %G for ISO 8601 year (week-based year)
• %g for ISO 8601 year (2-digit)

@lestrrat If you are fine with that I can make request.

Thanks

[lestrrat]

Sounds like a plan. If you can provide the code, that would be nice.

[flomedja]

Here is the MR