my body has a built-in wake up system, if i need to wake at 6am to get ready for work, which cou;d start at 7:30, i'll wake up at 5:30 and have time to fully escape dreamland before 6.

I have to be very careful, I try to stay between 6 and 8.
Any less doesn't really affect me, but I like to get plenty of sleep.

Any more than 8 and I start to grind my teeth, a lot. That causes me to wake up with tension headaches, and my mouth hurts.

I often went 3-4 days with no sleep when I was younger.
Wake up at 2AM, go to work at 3AM.
Work until 1PM and then go to my second job, work all day then back to work at my first job.

That used to be my normal Friday-Sat-Sun routine, with Monday off, then back to work on Tuesday.

I try to sleep at least six hours a day, but I can easily go fro 12.

I'm absolutely no expert on the matter, but I would say that an average of 2.5 hours of sleep is very unhealthy

Of course, everyone is different, and its certainly clear that some people need more or less sleep than others

For example, if you job isn't physically demanding, or that you don't put much physical stress on your body, then it would make sense to me that you body would not require as much sleep. That is, it is under my understanding that one of the main reasons why we sleep is for the body to perform routine, yet vital, maintenance on the body

But, my conclusion is that, in general, the minimum amount of sleep a person should get on average is precisely 7 hours (which is what I get). Further, I don't think its good to have inconsistent sleeping patterns, so I would also say that sleeping maybe 5 hours some days but making up for it on the weekend is just no good

8 hours, always. 10pm to 6 am.

I need 7-8, but usually only get 5 1/2 to 6. Constantly running a sleep deficit isn't healthy, but I just can't seem to get to bed early enough. I've recently been trying to go to be 15 minutes early every night until I get to get a least another hour, but even that's difficult (after going to bed at the same late hour for years).

I get about 7 hours a night, but I usually take an hour long nap everyday. So it evens out.

I sometimes get between 5 to 8 hours----but I still don't feel fully rested up when I wake up.

I am exactly the same, in both terms of when I need to get-up and when I go to sleep, I typically get around 5 hours but I feel fine at College; I often drift into a kind of sleep on the bus though which I guess isn't indictive of a healthy sleep schedule.

I could now be doing with more, I wake up and usually get straight up and ready but now I just cba moving, or is the natural process of being employed, all enthusiasm fades away.

I think I slept three and a half hours today wish I slept more

off with their beds!

Inconsistent. Last Friday, 2:30 AM-10 AM. Saturday 11 PM-6 AM. Sunday 12 AM-4 AM. Monday 1 AM-5 AM. Last night I fell asleep at 9:30 PM, woke up at 12 AM, stayed awake for an hour and fell asleep, woke up at 3 AM, fell back asleep, and finally woke up at 4 AM.
That averages at 5.4 hours of sleep, but that's not indicative of how much I get on a regular basis. I often have trouble falling asleep, I wake up very early, and I can pretty much guarantee that I will wake up like an alarm clock at least once in a night. Sometimes I go to sleep energized and wake energized the entire day, sometimes I go to sleep drained and wake up still drained, or any combination of those. Inconsistent is the best word I can use to describe, I don't know how much I really "need".

My natural sleep time is around 9 hours a night. I usually get 5-6 hours per night during the week, and catch up on the weekends if I can.