In what period did the timetable invented?
During what period was the timetable first introduced?
During what period was the timetable come into existence?
At what time was the calendar firstly devised?
During what period was the agenda firstly thought up?
At what time did the timetable firstly devised?
During what period was the calendar creation?
In which period was the timetable emerge for the first time?
When Was the Calendar Invented A Look at the History and
