solstice
nounUK /ˈsɒl.stɪs/
US /ˈsɑːl.stɪs/
The two days each year when the day is longest or shortest.
The summer solstice is the longest day of the year.
OTHER MEANINGS
2. The point in the sky where the sun reaches its highest or lowest position.
Astronomers mark the solstice as the sun's farthest point from the equator.
3. A time of greatest or least activity or change.
The festival marked a solstice of the town's fortunes.
4. Either of the two moments when the sun is farthest from the celestial equator.
The solstice occurs twice a year, in June and December.