On the average - 9 pm to 5 am. Some 15+ yrs ago I was diagnosed with sleep apnea, so I have to sleep with a mask on. This issue has a link to heart disease, so I take sleeping seriously. I have been know to alter my sleeping habits during deer season and college football season (Go Dawgs), but I still try to log 8 hours of good sleep. My breathing machine has an App that tracks the quality of my sleeping periods, meaning - deep sleep, core, & RIM, etc. So, all sleep is not necessarily good sleep....