UnreviewedUnreviewednarrowOne-letter-ish narrow form (here trimmed to two: "Mo", "Tu", …).
UnreviewedshortLocale short form ("Mon", "lun.", …).
UnreviewedlongLocale long form ("Monday") — for the column header's accessible name.
UnreviewedweekendSaturday or Sunday (locale-independent — by Temporal dayOfWeek 6/7).
A weekday column header, localized.