At what time did the timetable invented?
In what period was the timetable initially developed?
At what time did the calendar arise?
During what period was the schedule initially invented?
In which period was the schedule firstly imagined?
When was the schedule firstly established?
In what period did the timetable creation?
In which period did the calendar come about for the first time?
Who Invented the Calendar A History of the Calendar
