At what time did the agenda devised?
During what period was the timetable initially devised?
At what time did the timetable emerge?
When did the schedule initially created?
In which period did the timetable originally imagined?
During what period was the schedule initially devised?
In what period did the timetable inception?
In which period was the calendar arise for the first time?
How Did People Count Years Before BC and AD Medium