First Day Of Summer 2024 Time Zone. Solstice—the longest day of the year in the northern hemisphere and the shortest in the southern hemisphere—will occur on thursday, june 20, at 20:50. What exactly is the summer solstice?

The first day of summer arrives with the solstice this year on thursday, june 20, 2024 at 4:51 p.m. No world body has designated an official day to start each new season, and different schools of thought or traditions define the seasons.