At what time did the timetable originated?
During what period was the calendar initially established?
In what period did the agenda come into existence?
At what time did the timetable firstly invented?
In which period was the timetable firstly envisioned?
In which period did the calendar firstly established?
In what period was the agenda creation?
In what period was the timetable arise for the first time?
The Mayan Calendar 101 Calendar
