We have an alarm clock with a snooze and have had to teach ourselves not to take it back to bed with us - it lives across the room on our desk. But that's because we have to get up for lectures.
Would taking a nap in the afternoons help? Or pulling an all-nighter and going to bed at a reasonable hour the next day? (Not a good thing to make a habit of, but an excellent way to reset your sleep patterns.)