When Was the Calendar Invented A Look at the History and In what period did the timetable devised?
When did the timetable initially introduced?
During what period was the schedule arise?
At what time was the timetable initially devised?
During what period did the schedule initially imagined?
In what period was the timetable initially devised?
In which period was the timetable inception?
During what period was the agenda emerge for the first time?
