In what period did the agenda originated?
During what period did the timetable first established?
In what period did the timetable arise?
In what period was the schedule initially invented?
During what period was the calendar firstly thought up?
In which period did the timetable firstly established?
During what period was the timetable generation?
In which period was the schedule arise for the first time?
Mesoamericans Have Been Using a 260Day Ceremonial Calendar
