The lunar module landed at 20:17 on July 20th and took off at 17:54 on July 21st.
This represents 21 hours and 37 minutes duration.
They were in space for 8 days..
Apollo 11 had only one moon walk , so it was for 21 hours and 38 minutes.
Apollo 11 stayed on the surface of the moon, for about 26 hours.
The entire Apollo 11 mission lasted 8 days 15 minutes.
It was launched on the 16/7/1969 and landed on the 20/7/1969. that is a little over three days.