Count Each Day of the Week Within a Period

・Input in the Japanese calendar system is available starting from January 1, Meiji 6 (1873), when the Gregorian calendar was adopted.
・For Western dates, the Julian calendar is used up to 1582-10-04; the Gregorian calendar is used starting from the following day (October 15). Dates before the Common Era cannot be entered.
・The pop-up calendar is available starting from 1582-10-15, when the Gregorian calendar was adopted.