[Taldres]

Profiles can now show the person's current local time next to their location and website, like GitHub does, e.g. 11:06 (UTC +02:00).

It is off by default. Settings → Timezone has a new checkbox, "Show my local time on my profile", which is only available while a timezone is set. Clearing the timezone turns it off, on the server too, so a profile never shows a time without a timezone behind it.

• New users.show_local_time boolean, default false, saved together with the timezone through the existing PUT settings/timezone.
• LocalTime renders nothing on the server and ticks every minute in the browser, so the server's clock is never shown as the reader's.
• The offset comes from Intl, so it follows daylight saving time. A zone without an offset reads UTC.
• The timezone itself was already public once set (tooltips show it). This only adds control over whether the profile shows the time.
• The data export includes the new field. The knowledge base is updated.

Relates to #669, #737 (other open PRs on timezone and time formats). This reuses the timezone setting and does not touch their formatting.

Tests

• Feature tests for the controller (opt in, opt out, no timezone, invalid value), the action, the export and the profile payload for guests.
• A unit test for the UTC offset, including daylight saving time.
• Checked by hand in the browser: checkbox disabled without a timezone, the save button enabling and disabling, the line on the profile, and unsetting the timezone.
• composer test passes except the 100% coverage step, which needs a coverage driver I don't have locally.

Preview

[Taldres]

Would you be interested in this opt-in local time feature for profiles? Happy to adjust the approach if you have a different direction in mind.

[xHeaven]

@nunomaduro I think this looks good, has a migration in it though so needs your call.

[brendt]

Since auto deploy is disabled, I'll merge this already and @nunomaduro you can take care of it when you're back