When Neil Armstrong first set foot on the Moon during the Apollo 11 mission on July 20, 1969, it was daytime on the lunar surface. The landing occurred in the lunar region known as the Sea of Tranquility (Mare Tranquillitatis), and the local time there was morning.
The lunar day and night cycle is different from Earth's, as the Moon takes approximately 29.5 Earth days to complete one orbit around our planet. During this time, the Moon goes through phases, with about 14 days of daylight followed by 14 days of darkness. The specific time of landing during the lunar day was chosen to maximize visibility and ensure better lighting conditions for the astronauts' activities on the surface.