When was the calendar invented?
In which period did the schedule first established?
In what period did the schedule emerge?
In which period was the timetable originally invented?
In which period was the schedule originally thought up?
In what period was the calendar firstly introduced?
During what period did the calendar inception?
When was the timetable come about for the first time?
- 04/13/01:39
- Mesoamerican calendars Wikipedia
