CPAPtalk.com

When I got my second machine in June, 2015, the SD card had info on it from March, 2015. The machine was brand new with zero hours on it. I thought the data on the card may have been from some sort of factory testing.

You need to consider AT LEAST 4 hours EVERY night as mandatory.
More is that much better for you.
Any less, insurance will not pay--and you reap the woes of cheating yourself.