My personal definition would be from about 10pm through till about 6am - in other words, not waking up in the wee hours. I'm living in hope of getting to 7pm-7am one day...maybe...please...

The official definition is any 5 hour stretch - pfft to that.

ATM I'm happy if I can get an uninterrupted 3 hours of sleep. I don't feel quite so much like the living dead if I've managed 3 hours of sleep without being woken - that must be how long it takes me to complete a sleep cycle IYKWIM. Anything less than that is SO much harder to cope with, I quite literally stagger out of bed LOL.