@jklymak I would love to take this up

That would be great! Let us know if you need guidance.

@sameshl are you on this, or else I could get started on this.

@abhinuvpitale You can get started on this.

@jklymak I need to add the tests in the test_dates.py right?
A little guidance on the test content would be helpful.

That’s right test_dates.py. The content would be checking that the formatter makes the correct format if you change format and zero_format

Since this thread seems kind of dead, I wrote 2 tests and have code for it (it's on a branch on my forked copy of matplotlib); however, when I run tests locally, a lot of them fail because dateutil throws a deprecation warning. Since this is not matplotlib, should I ignore it? Or should I do something?

I guess that depends on why dateutil is throwing a deprecation warning?

Full trace:
trace.txt
The relevant line is,
DeprecationWarning: fractions.gcd() is deprecated. Use math.gcd() instead.

Thanks. That’s dateutils issue so fee free to ignore it. Or report it to them if you can make a non matplotlib mi nimble example.