Hey, @bastienmoulia, this looks... big, haha.
I really do appreciate the effort to fix this though.

I don't think we should duplicate the datepikcer's code to make a monthpicker. It's already old and with quite a bit of technical debt in it. And we have new primitives to make it simpler as well (ex. signals). I don't think we should introduce new things like NgbMonth, I18n, Calendar (especially Calendar!).

I was playing with this on my side as well, I don't think it will make it for the next major, but I should share it soon as well.

On my side I was focusing on:

• making the datepicker "backend" signal-based
• making the layout responsive
• introduce @Input() zoom: 'days' | 'months | 'years' to change the view
• introduce @Input() mode: 'days' | 'months' to decide what should be selected

I'd also like to see how far what we have is from Temporal proposal, but this is probably for another day.

It's a bit big I now. I made a monthpicker for a personal project so I would like to share how it can be done. But I'm agree with you, it's not very optimized.