When was the agenda devised?
In which period was the timetable first developed?
In which period did the timetable come into existence?
In what period was the calendar firstly devised?
In which period was the timetable firstly imagined?
In what period was the agenda firstly introduced?
At what time did the agenda creation?
In which period was the calendar come about for the first time?
The Mesoamerican Calendar Ancient Shared Time Keeping
