Add UTC timezone support to timepicker

[jonrimmer]

Is your feature request related to a problem? Please describe.

When building apps that work across timezones, it is frequently necessary to show/capture dates and times in a different timezone that the user's local one.

BsDatepickerConfig now has a useUtc property for showing/capturing UTC dates/date ranges, but timepicker does not have the same support.

Describe the solution you'd like

Add support for an equivalent useUtc property to Timepicker / TimepickerConfig.

Describe alternatives you've considered

Somebody already did all the work to add full timezone support to timepicker in this PR:

#4747

But nobody could be bothered to review it, so the author closed it. Maybe it could be resurrected?

[daniloff200]

Well, 4747 is really outdated, and it's sad, that the author of this closed it :(
Sad, that he doesn't tag any person, which was merging / reviewing code at the time, or, author of the library :(
I'm gonna try to resolve all conflicts, or, create a new PR, and see, what can be done here

[daniloff200]

lol, do the @jonrimmer and @jonr-elsewhen are exactly the same person? 🤣

[jonr-elsewhen]

@daniloff200 Almost, one is me at work, one isn't ;-)

[juicyarts]

Sorry for the circumstances. Our PO decided that this is not important any more after some days of work on it.. Let me know if i can help

[daniloff200]

hey @juicyarts !
I fixed all the conflicts in your PR, but, there are some test failures, and I'm not 100% sure, how to fix them

[DanielMcAssey]

Can this be fixed/implemented? Its been a year and a half.

[daniloff200]

@DanielMcAssey not sure about that right now, we've made a huge reworks during this year and 4747 PR is really abandoned & outdated and requires a big amount of changes

[juicyarts]

Hey folks. Sorry for this mess. As much as i would like to help out, i'm too far away from angular and this library for some years now and not sure if i will manage to get back into it to finish the ideas from three years ago. I would start a last try this weekend to see if this can be properly migrated and cleaned up in a way that you can at least proceed to finish it. If this does not result in a meaningful outcome i'll get back here next week and inform you. If thats the case i would suggest you don't rely on me for this any longer and start things from scratch.

[juicyarts]

I added #6322 for the Utc behaviour alignment with the datepicker and https://github.com/juicyarts/ngx-bootstrap/pull/1 (based on the utc branch, no MR opened yet) for the offset addition if needed. #4747 was closed in favor of these two branches.

Unfortunately i have a lot of trouble running (all) the tests suites locally so if the general behaviour is what was requested maybe someone else could take over here to add dedicated e2e tests and verifying the unit tests are running as needed. I'm sorry that i can't contribute much more for the time being

[on3dd]

No updates for almost 5 years? The fact that timepicker uses the timezone literally makes no sense in real world apps

[juicyarts]

I'm out of this topic, this just halted years ago.