When is the first OFFICIAL day of fall/autumn?

Question

When is the first OFFICIAL day of fall/autumn?

Answer 1

I believe it's the 22nd of September.  

Answer 2

The first day of autumn falls on Monday September 22 of this year.

On that day in 1977, Elton John released his Diana tribute "Candle in the Wind 1997"

In 1987, Red Sox Wade Boggs tied AL record of 200 hits for 5 straight seasons

and in '91, California University made the Dead Sea Scrolls public