What's the longest time you've stayed awake in a day??

The longest that I've managed to stay awake was 36 hours and that was most likely only due to the fact that I'd slept for 12 or more hours every day of the week leading up to those 36 hours. I definitely would not attempt it again unless it was completely necessary because my ability to comprehend things and type correctly diminishes greatly when I pull a stunt like that.

there were 2 consecutive days when i didn't doze for a single second.that was the time i was engrosed in harry potter books.In those 2 days I finished the first 5 books of the series.those 2 days were great.usually i go to sleep at about 12am because i have college from 6.30 am.So i have to fall asleep by midnight.