According to the Byzantine calendar, the world is created on this date.
The Byzantine calendar was a Julian calendar used by the Eastern Orthodox Church from c. 691 to 1728 and was the official calendar for the Byzantine Empire from 988 to 1453. It was also the standard calendar used in Russia from c. 988 to 1700.
The years of the Byzantine calendar started on September 1 to mark when Byzantine Christians believed the world was created by God.
The calculation of when God created the world was based on information gathered from the Septuagint version of the Bible.