In what period was the schedule created?
During what period did the calendar initially devised?
In which period did the calendar come into existence?
During what period did the calendar initially invented?
In which period was the agenda originally imagined?
In what period did the agenda firstly introduced?
During what period did the timetable creation?
During what period did
the calendar arise for the first time?
Mesoamericans Have Been Using a 260Day Ceremonial Calendar
