Longest And Shortest Day Of The Year 2025 Dates. The winter solstice — the exact moment when the sun appears farthest south in the sky — happens at 4:20 a.m. For us in the northern hemisphere, the june solstice marks the shortest nights and longest days of the year.
The summer solstice marks the date of the longest period of daylight and the shortest night of the year, when the earth’s north pole has its maximum tilt towards the sun. In 2025 the summer solstice will occur on thursday 20 june at 21.51 bst (20.51 gmt).