dayside
/ˈdeɪsˌaɪd/Definitions
1. noun
The side of the Earth that faces the sun, especially during the day.
“The satellite will orbit on the dayside of the Earth to collect solar radiation data.”
2. noun
The day side of a planet or moon, especially one that orbits a star.
“The dayside of Venus is extremely hot due to its thick atmosphere trapping heat.”