actually, the week before my exams my consumption peaks.
for example monday I had an organic chemistry exam. I procastinated studying way too long, so on sunday, I realised I had only read trough chapter 1 but still had to study basically everything. so I got into study-mode, start up was a little slow(watching trailer park boys while drinking coffee and vaping), but eventually I studied untill 3 in the evening or so, without weed I wouldn't have managed to keep my concentration up for that long. but everytime when I felt my concentration was slipping, the point where what I was reading wouldn't stick anymore, I would take a few hits from the bong next to me, and suddenly my concentration came back and I undewrstood what I was reading again, and my study-speed went back to the normal level.
(during my highschoolexams I also tried studying sober, since if studying high worked studying sober should work better I thought, but it turned out that if I didn't smoke/vape I would just sit around watching tv all day instead of studying. when actually taking the exam I'm never high though, only during the studying for it)