Let's say you want your camera to take a picture every 20 minutes. When the camera is in set up mode, you will press the menu button. Scroll over to the PIR, now arrow down to the time lapse. Press OK, scroll down to on, press OK again. Now you will set whatever time period you would like to take a picture. If you wanted one every 20 minutes, you would scroll over to the minutes (MM) and put in 20. Notice it is set up as HH:MM:SS; this is hours, minutes, and seconds. Press OK to save. Press menu again, delay should be off time lapse should be on and timer off. NOTICE, it will not take any pictures of motion during this setting- only pictures every 20 minutes.