How long apollo 11 on moon?

Eagle settled onto the Sea of Tranquillity at 20:17 UTC on 20 July 1969 with very little manoeuvring propellant left in its tanks. The flight plan had called for a rest period before the walk; the crew asked to go outside first and mission control agreed. Armstrong opened the hatch some six hours after landing, and both men were back inside, repressurised and working through housekeeping, long before the ascent stage fired to rejoin Michael Collins in Columbia. Total time with the landing legs on the Moon: 21 hours 36 minutes.

The moonwalk itself lasted 2 hours 31 minutes and was crowded. Armstrong scooped a contingency soil sample within minutes, insurance against an emergency lift-off; then came the flag, the plaque, a televised call from the White House, a seismometer, a laser retroreflector and the collection of roughly 21 kg of rock and dust. Both men also spent real time learning to move in one-sixth gravity, where a loping hop turned out to be more efficient than walking.

The lunar module was a minimal machine. Its life-support consumables, battery capacity and cooling water were sized for a brief visit, and the ascent had to occur within a window that placed the two spacecraft in workable relative geometry. Above all, Apollo 11 was a test of whether landing and leaving worked at all, not an expedition. The geology came later, when the J-class missions carried a rover, larger consumables tanks and crews who stayed three days.