I'm convinced my internal "day" clock is greater than 24-hours because my sleep cycle is always drifting forward. Years ago, I maintained a relatively normal life by going to bed around 2 or 3am. Then it was 3 or 4am. Then 4 or 5am. And I've actually struggling to hold onto a 5-6am bedtime for a while now. It wants to creep forward. Most days it's more like 6-6:30am. My schedule is so far shifted from the norm now that having to be up early for an appointment is quite difficult and means I'll grab barely enough sleep to even function. It's kind of crazy and I often wonder how many more years of time shifting it would take before I found myself going to bed at 11pm like normal person for a while.
There's clearly a genetic component to this because my entire family is prone to it. My younger brother and I seem to have it worst, though. He manages a normal job by having special hours just for him. He goes in a few hours later than everyone else and stays a few hours later than everyone else. On the weekends, it's not uncommon for my brother and I to be having conversation and snacks at 3 or 4am while the man slumbers away in with his normal sleep pattern.
But here's the odd glitch in this whole thing: my sleep cycle is also affected by seasonal light shifts. As the days grow longer in springtime, my days begin to contract. They aren't contracting really, they're just drifting backwards. I start getting tired earlier and going to bed earlier. It's nothing too dramatic, but I always find that around this time of year, my sleep cycle drops back an hour. Instead of going to bed around 6:30am, I've been going to bed around 5:30am. Still crazy, but at least it's a shift in the right direction right?
Then we move the clocks forward, putting me right back where I was.
Come fall, the opposite happens. The days contract, I find myself staying up an hour later and gain no ground when we move the clocks back. Very annoying.