When did the calendar invented?
At what time was the calendar first developed?
In which period was the agenda emerge?
During what period was the calendar firstly created?
In which period was the calendar initially conceived?
During what period was the calendar firstly introduced?
In which period was the timetable creation?
In what period was the schedule come about for the first time?
The History of the Advent Calendar I Oxford Open Learning
- 04/13/01:39
- The Maya Calendar System Smithsonian Institution
