According to the definition that fall begins at the autumnal equinox and ends at the winter solstice, the first full day of fall in 1946 was...
October 23, 1946, was a Wednesday.
March 4, 1946 was a Monday.
September 12, 1946 was a Thursday.
November 6th, 1946 fell on a Wednesday.
October 12 1946 was on a Saturday.
November 5th 1946 was a Tuesday.
June 4 1946 was a Tuesday.
It was a Thursday.
Wednesday
Monday.
Friday
Tuesday