In what period was the agenda originated?
At what time did the agenda first established?
In what period was the schedule come into existence?
In what period did the schedule originally created?
During what period did the schedule firstly conceived?
When did the schedule initially introduced?
During what period did the timetable inception?
During what period did the calendar arise for the first time?
- 04/13/01:39
- Mesoamericans Have Been Using a 260Day Ceremonial Calendar
