Bug 234830 – Intl.DateTimeFormat dateStyle: medium has 'at' between date and time when it should not

• Status: RESOLVED
• Resolution: WONTFIX
• Component: New Bugs

new Intl.DateTimeFormat('en-US', {dateStyle:'medium', timeStyle:'short'}).format(new Date());

Jan 3, 2022 at 2:26 PM

In Chrome and Firefox it is

'Jan 3, 2022, 2:33 PM'

CLDR locale data is this:

"dateTimeFormats": {
              "full": "{1} 'at' {0}",
              "long": "{1} 'at' {0}",
              "medium": "{1}, {0}",
              "short": "{1}, {0}",

[Yusuke Suzuki]

Thanks,

ECMA402 does not require 1:1 CLDR conformance. Intl.DateTimeFormat will generate reasonable results for each platforms.
In Apple platforms, we are using AppleICU, which is customized fork of ICU, and it has various extensions (some features that only exists on AppleICU, and some CLDR tweaks based on Apple HI etc.).

And AppleICU intentionally uses "at" here to follow Apple HI.
https://github.com/apple-oss-distributions/ICU/blob/ICU-66112/icuSources/data/locales/en.txt#L230

[Radar WebKit Bug Importer]

<rdar://problem/87077451>