How many days did it take Apollo 11 to reach the Moon?

Liftoff took place on July 16, 1969, at 13:32 UTC, and the landing on July 20 at 20:17:40 UTC: four calendar days between the two dates, and, in mission time, 102 hours and 45 minutes. The itinerary was tightly scripted: leaving Earth orbit on the first day, a couple of days cruising toward the Moon with the lunar module docked to the command module, entering lunar orbit on July 19 at 17:21:50 UTC via a retrograde burn of the main engine, and, on the 20th, separation of the Eagle and the powered descent.

The duration isn't set by distance but by trajectory. A faster flight requires spending more propellant on departure and, above all, much more on arrival, because you have to slow down what you've accelerated: the higher the approach speed, the bigger the burn needed to avoid overshooting. Apollo used an almost energy-free path, letting the spacecraft fall toward the Moon and adjusting course with small burns. Robotic probes can afford slow routes, taking weeks or months, with increasingly wide Earth orbits; a crew cannot, because it consumes water, oxygen, and safety margin.

Armstrong and Aldrin spent 21 hours and 36 minutes on the surface before firing the ascent engine and rejoining Columbia. The mission ended on July 24 at 16:50:35 UTC with splashdown in the Pacific, after 195 hours, 18 minutes, and 35 seconds of flight and 953,054 miles traveled between the outbound trip, the lunar orbits, and the return.