When Was the Calendar Invented A Look at the History and
At what time did the timetable devised?
In which period did the schedule initially developed?
In which period did the schedule emerge?
During what period was the schedule originally devised?
In which period did the schedule originally conceived?
In what period did the calendar initially established?
During what period was the calendar inception?
At what time was the timetable come about for the first time?