ui: Follow `user_settings.twenty_four_hour_time`

[chrisbobbe]

When we show timestamps, for example on messages in the message list, we should format them according to the user's setting:

• user_settings.twenty_four_hour_time true: "13:52"
• user_settings.twenty_four_hour_time false: "1:52 PM"

This is something we did in the zulip-mobile legacy app.

In addition to the timestamps on messages in the message list (which is the most visible and most important place), this should apply to everywhere else that we show a time of day to the user. To find other such places, try git grep DateFormat.

References

• Help center doc
• UserSettings.twentyFourHourTime in lib/api/model/initial_snapshot.dart
• UserSettingsUpdateEvent in lib/api/model/events.dart

[c-o-d-e-y-o-d-a]

I would like to work on this issue if it has not been assigned to anyone else.

[chrisbobbe]

Please see the Zulip project's guide to claiming an issue: https://zulip.readthedocs.io/en/latest/contributing/contributing.html#in-other-zulip-repositories

In particular:

In your comment, describe what part of the code you’re modifying and how you plan to approach the problem, based on what you learned in steps 1–4 above.

[Gaurav-Kushwaha-1225]

Hi @chrisbobbe,

I would like to take up this issue.

I have started working on it and have achieved some successful results.
You can review my changes here: Compare Changes.
Please permit me to continue working on this issue.

Additionally, I have taken screenshots after changing the twenty_four_hour_time preference in my account via the web app:

12-Hour Format	24-Hour Format

Currently, some checks are failing. I will look into them once the issue is assigned to me.

Looking forward to your feedback! 🚀

[chrisbobbe]

Requested in launch feedback: https://chat.zulip.org/#narrow/stream/48-mobile/topic/12-hour.20time.20format/near/2216815