Summer Solstice 2025 United States Calendar. You can use the us holiday calendar and date calculator to plan this and other important national,. It also lists astronomical sunrise and sunset timings on summer solstice day.

The first day of summer, also known as the summer solstice, will occur on saturday, june 21, 2025, at 10:42 pm edt. This is the longest day of the year and marks the start of summer in.