The Calendar
What the atlas records for this date, across the traditions it covers.
Observed On This Date
Observed every October 9. First declared World Post Day at the Universal Postal Union's 1969 Congress in Tokyo. National postal services mark the day with stamp exhibitions and related events.
This Week In Philosophy History
Dates for the Hebrew and Islamic calendars are the tabular reckoning, which is what a printed calendar prints. Communities that begin a month on a sighted crescent may differ by a day, and differ from one another by place.