2017年04月 / Julian calendar Wikipedia
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During what period was the agenda invented?
In what period was the timetable first devised?
In which period was the timetable emerge?
In which period did the schedule originally invented?
In which period did the schedule initially conceived?
During what period did the timetable initially created?
In what period was the schedule generation?
At what time was the timetable arise for the first time?