Start of seasons

"The app has different background color for weeks within each season.

Spring: Starts at Swedish Vårdagjämningen, 22nd of September
Summer: Starts 1st of June
Fall: Starts at Swedish Höstdagjämningen, 22nd of September
Winter: Starts 1st of December." - README.md

Spring and fall seem to start on the same day. Is this accurate?