Add class names allowing for styling specific weekday tile headers

[tilden]

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Description

I'm working on a calendar app where I want Sundays to be highlighted in red and Saturdays to be highlighted in blue (this is fairly typical design for physical calendars in Japan).

For the day tiles themselves, the tileClassName prop makes it fairly easy to apply this custom styling to Saturdays/Sundays. However, as far as I can tell, there's no way to add a custom style to the title row (react-calendar__month-view__weekdays).

The closest provided class is react-calendar__month-view__weekdays__weekday--weekend, which allows me to style the weekend tile headers with a different color than weekdays. However, there's no differentiation between Sunday and Saturday with this class alone. I can attempt target Saturdays with Nth child selectors, but this doesn't work properly if the user's locale specifies weeks starting on Monday instead of Sunday (or vice-versa).

Proposed solution

Add targetable class names to the weekdays header tiles that uniquely identify each day. Something like react-calendar__month-view__weekdays--day0, etc. The numbers could just be the ones coming from Date.prototype.getDay() for consistency with other JS date functions. (Where "day 0" is always Sunday and "day 6" is always Saturday.).

Alternatives

Alternatively, there could be a prop that functions like tileClassName, but for header tiles.

Additional information

Example of the visual I'm trying to achieve: