A Brief History of Time and Calendars MacTutor History of At what time did the agenda devised?
At what time was the calendar initially devised?
At what time was the timetable arise?
In which period did the schedule firstly devised?
During what period was the timetable firstly conceived?
When was the timetable firstly devised?
During what period was the agenda inception?
During what period was the timetable arise for the first time?
