When did the calendar invented?
At what time was the schedule initially established?
In which period did the schedule emerge?
In which period was the schedule firstly devised?
During what period was the schedule originally conceived?
At what time was the schedule initially introduced?
In what period was the timetable inception?
During what period was the agenda emerge for the first time?
When did the calendar invented?
At what time was the schedule initially established?
In which period did the schedule emerge?
In which period was the schedule firstly devised?
During what period was the schedule originally conceived?
At what time was the schedule initially introduced?
In what period was the timetable inception?
During what period was the agenda emerge for the first time?
