BREAKING(datetime): replace utc with timeZone option

[timreichen]

Changes
This PR changes the utc boolean option to timeZone with explicit "UTC" value option.

Reasoning
This makes the option extendable if needed and aligns the api to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleTimeString#using_options

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.21%. Comparing base (4432ba1) to head (e94d96e).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5647      +/-   ##
==========================================
- Coverage   96.21%   96.21%   -0.01%     
==========================================
  Files         469      469              
  Lines       38181    38179       -2     
  Branches     5539     5538       -1     
==========================================
- Hits        36735    36733       -2     
  Misses       1404     1404              
  Partials       42       42              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[iuioiua]

Seems fine to me.

[kt3k]

Our formatter seems only supporting utc and local timezones? (because we use Date under the hood). ref.

std/datetime/_date_time_formatter.ts

Line 154 in 96d7020

const utc = options.timeZone === "UTC";

Doesn't this give the false sense of other timezones being supported?

[timreichen]

Our formatter seems only supporting utc and local timezones? (because we use Date under the hood). ref.

std/datetime/_date_time_formatter.ts

Line 154 in 96d7020

const utc = options.timeZone === "UTC";

Doesn't this give the false sense of other timezones being supported?

I think it is clear that only UTC is supported, because it is the only valid value. If you want we can add a check and throw an error for invalid timezone values (other than UTC here, or maybe even better case insensitive) like in Intl.DateTimeFormat.

[iuioiua]

My take: it doesn't matter too much, either way.

[kt3k]

LGTM