5 days - the first three were down to long working hours, the final two courtesy of drugs and parties. Every thing goes a bit sideways after day three, concepts like 'tired' and 'well rested' no longer have any meaning, and everything you experience feels more like a memory than a real time event. Your brain also forgets how to turn off - I tried to get some kip in after day three, but couldn't and gave up. When I did go to sleep, I was out for 24 hours and felt worse when I woke up than when I went to bed, and spent about 12 hours mooching round my room, smoking weed and feeling sorry for myself before sleeping for another twelve. Never again.