endOfWeek method
Friday of this date's Persian week, date-only.
Throws ArgumentError when that Friday is after PersianDate.max.
Implementation
PersianDate endOfWeek() => addDays(7 - weekdayPersian);Friday of this date's Persian week, date-only.
Throws ArgumentError when that Friday is after PersianDate.max.
PersianDate endOfWeek() => addDays(7 - weekdayPersian);