I have yet to encounter a person with a worse sleep cycle than me. I have the innate ability to stay up for 24+ hours and sleep for 16+.
I've once stayed up for almost 72 straight which involved a work day and a camp out for Jordans. I've also slept for 22 hours without waking up to go to the bathroom or drink or anything.
I rarely work more than 2 days in a row, so that further hurts my sleep pattern. I usually get 3-4 hours at most before work, and wind up coming home and sleeping for another 3-4 before staying up to 3am and then either getting up at 6am for work or sleeping til the afternoon if I'm off.
But I would suggest trying to tire yourself out physically so you pass out before midnight and try to get up before noon, and keep shortening the days until you reach your target times of sleeping and awaking. Or you should deprive yourself of sleep until the evening and go to sleep very early (say 7pm) and sleep for 12 hours til (7am). Waking up that early should get you to bed before midnight.