Add methods to Holiday
interface that is related with substitute holiday.
Original
If holiday is substitute holiday, Original
method returns original holiday.
ex:
d, _ := flagday.PublicHolidayOf(2009, 5, 6)
fmt.Println(d.Kind() == flagday.SubstituteHoliday) // true
fmt.Println(d.Original().Time().Format("2006/1/2") // 2009/5/3
IsSubstituted
If holiday is original holiday, IsSubstituted
method returns true
.
ex:
d, _ := flagday.PublicHolidayOf(2009, 5, 3)
fmt.Println(d.IsSubstituted()) // true