Who Invented the Calendar A History of the CalendarIn what period did the calendar invented?
In which period was the timetable first developed?
In which period was the timetable emerge?
In which period did the schedule firstly invented?
In which period was the agenda firstly imagined?
During what period did the calendar firstly created?
In what period did the schedule inception?
At what time was the timetable come about for the first time?