11 September

September 11 is the 254th day of the year (255th in leap years) in the Gregorian calendar. There are 111 days remaining until the end of the year. This date is slightly more likely to fall on a Tuesday, Friday or Sunday (58 in 400 years each) than on Wednesday or Thursday (57), and slightly less likely to occur on a Monday or Saturday (56). It is usually the first day of the year in the Coptic calendar and Ethiopian calendar (in the period AD 1900 to AD 2099).

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Wikipedia