startOfWeek method
Saturday of this date's Persian week, date-only.
Throws ArgumentError when that Saturday is before PersianDate.min.
Implementation
PersianDate startOfWeek() => addDays(1 - weekdayPersian);Saturday of this date's Persian week, date-only.
Throws ArgumentError when that Saturday is before PersianDate.min.
PersianDate startOfWeek() => addDays(1 - weekdayPersian);