During what period was the timetable invented?
When was the calendar first developed?
At what time did the agenda come into existence?
During what period did the timetable firstly invented?
In which period did the timetable originally imagined?
During what period was the agenda initially introduced?
At what time was the timetable generation?
At what time did the calendar emerge for the first time?
Exploring the history and evolution of Advent calendars NPR
