At what time
did the calendar devised?
In what period did the timetable first developed?
At what time did the schedule emerge?
In which period was the calendar originally devised?
In which period was the timetable firstly thought up?
At what time did the schedule initially created?
At what time was the calendar generation?
In which period did the schedule arise for the first time?
- 04/13/01:39
- Keeping time The origin of BC and AD
