September 15, 2023, was a Friday. Here are some additional details about that day:

• It was the 258th day of the year 2023 in the Gregorian calendar, with 107 days remaining until the end of the year.

• It was the first day of Rosh Hashana, a Jewish observance that marks the beginning of the Jewish New Year.

• It was also National Cheese Toast Day, National Double Cheeseburger Day, National Online Learning Day, and Make a Hat Day, among other observances.

• Some multi-day events that started on September 15, 2023, included National Hispanic Heritage Month and Chef Appreciation Week.

• Some other notable events that happened on September 15th in years past were also listed on some of the search results.