In which period was the timetable originated?
In what period did the timetable initially devised?
In what period did the timetable come into existence?
At what time was the calendar firstly devised?
During what period did the schedule initially conceived?
During what period was the timetable initially created?
At what time was the schedule creation?
At what time was the agenda arise for the first time?
The Mesoamerican Calendar Ancient Shared Time Keeping
