Actually I like it, and while I wouldn't call it beautiful, I think it has utility just as it is. I'd consider porting it to an iPhone or Android app, too - it might find the biggest audience there and more recurring users.

While I don't think there's a huge amount of mileage in personalising it into a sleep log system, I do think there's some value in reversing it:

It is now 23:27. If you assume it takes me 14 minutes to fall asleep, what are the optimal time choices I should set my alarm for?