Day Name Format Changed in v8.5.0 (Breaking UI)

[yim-jj]

In versions up to v8.4.0, day names were displayed as follows:

Korean: 일, 월, 화, 수, 목, 금, 토
Japanese: 日, 月, 火, 水, 木, 金, 土
English: Su, Mo, Tu, We, Th, Fr, Sa

However, starting from v8.5.0, the day labels changed to the full day names:

Korean: 일요일, 월요일, 화요일, 수요일, 목요일, 금요일, 토요일
Japanese: 日曜日, 月曜日, 火曜日, 水曜日, 木曜日, 金曜日, 土曜日
English: Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday

This change causes layout breaks in our UI because the component now uses much longer labels, which were not used in previous versions.

Is this an intentional change?
If so, could there be an option added to choose between short and long weekday formats?
If not, this seems to be a regression introduced in v8.5.0.

Thanks!

[martijnrusschen]

No this isn't intentional. I will trace down where this changed and figure out a path forward.

[martijnrusschen]

Summary

• Bug introduced: v8.5.0 (commit 311cc86)
• Bug fixed: v8.7.0 (commit 81e9c6f)
• Affected versions: v8.5.0 and v8.6.0

The Bug

• Commit 311cc86 ("Improve calendar header accessibility by adding screen reader text for week numbers") added a element with the full weekday name.
• However, it used the generic sr-only class instead of the namespaced .react-datepicker__sr-only class that exists in the datepicker's stylesheet.

This caused the full weekday names (e.g., "Sunday", "Monday") to be visible instead of the short names (e.g., "Su", "Mo") for users who:

1. Don't have a global .sr-only class in their CSS
2. Are using CSS modules which transform class names

The Fix

Commit 81e9c6f fixed this by changing sr-only to react-datepicker__sr-only, which is the properly scoped class defined in the datepicker's own stylesheet.

The fix has already been released in v8.7.0. Users experiencing this issue should upgrade to v8.7.0 or later.