Which brand and model number specifically?
Leviton Decora manual says:
"PR180 operates by detecting motion (such as body heat) within its field-of-view (area of coverage) and automatically switches lights ON. When motion is no longer detected, lights remain ON for a selected time and automatically switch OFF.
Adjustable light and time-delay controls are located on the front of the device."
The manual is not specific about set times.
In any case, the device has off-delay timing circuit, so once infrared heat is no longer sensed, the delay period begins, and once the delay period expires, the device is switched off.
Delay timing circuits are common for many home and industrial applications.
As a general rule, delay timers can be set for different time durations, however the Amazon page that sells PR180 product does not specify available time settings either.
Legrand RW3U occupancy sensor spec sheet says adjustable time delay 15 seconds 5 minutes, 15 minutes and 30 minuteshttp://www.amazon.com/Legrand-RW3U603I-Occupancy-Vacancy-Decorator/dp/B005FMLL5G
Here is manual delay-time switch Tork SS20 SS13 where you can 'fine-tune' the delay circuit, but my experience is that exact 5 minutes is not easily set:http://waterheatertimer.org/images/Paragon-ET-series-243.jpg
GE 15318 switch offers 5 minute, but there is no guarantee that you can get 5 minutes exactly:http://waterheatertimer.org/images/GE-15318-countdown-timer.jpg
My conclusion is that there are very limited delay-time choices with this model number, or device is defective and suggest to call Leviton.