0.9.1-alpha.60

Patch Changes

• c459084: feat(calendar): a month, and the day chosen in it

  P5.26b, and the first of the date family: the DatePicker, the AgendaCalendar, the RangeCalendar and the DateRangePicker are all this grid with something around it.

  The month on screen is state of its own, separate from the chosen day. Paging through months is not choosing: a calendar that jumped back to the chosen month every time you looked at the next one would be unusable, and one that chose a day because you paged past it would be worse.

  The grid is always six weeks, never five for a short month — a grid that changed height between March and April would move everything under it twice a year. Days from the months either side fill the ends, muted but still choosable: a calendar that refused the 1st of next month would be refusing a date you can see.

  Calendar.Grid takes a function, and it is the one place in this library that does. Forty-two cells are generated from a month rather than written, so there is nothing to compose against — asChild merges into one element and a slot list cannot enumerate a month. It stays two lines at the call site because a day is a date plus the calendar around it: Calendar.Day reads chosen, outside-the-month, out-of-bounds and today off its own date.

  The chosen day is bgSelected / fgSelected rather than a variant axis — the Checkbox's roles for the Checkbox's reason: forty-two cells share one resolution, and a raw color written as an axis would stop reaching the chosen day the moment it became the chosen one.

  The chevrons go dead at the bounds. A step that would land on a month with no selectable day has nothing to show, and a chevron that stays lit while it stops working is the worst of the three options. Bounds compare by day, not by instant: a maxValue written as new Date() carries the current time, and an instant comparison would refuse the rest of today.

  The week starts where the locale says. Intl.Locale's week info answers it properly where it exists — Saturday-first locales are real, and a hand-kept list of Monday-first languages has never included them — with that list as the fallback, not the source.

  utils/dates.ts is new and tested, twenty-eight cases. Two of its functions exist because the obvious version is wrong: addMonths clamps to the end of the target month, since January the 31st plus a month is the 31st of February and Date rolls that to the 3rd of March; and addDays goes through the day-of-month rather than through milliseconds, since a day is not always 86 400 seconds and adding that many across a daylight-saving boundary lands an hour into the day before.