The Maya Calendar System Smithsonian InstitutionDuring what period did the agenda devised?
During what period was the agenda first established?
In what period did the calendar arise?
During what period was the timetable originally created?
In which period did the schedule originally conceived?
In which period was the agenda firstly introduced?
At what time was the timetable creation?
During what period was the timetable come about for the first time?