How long does it take to level up in the various D&D editions?

Between the end of one session and the start of the next, regardless of IC elapsed time.

>>51955351
>>51955365
This. D&D settings run on spiral power.

I remember 3.5 had rules for required downtime in order to level up in the DM's guide, but it really just got in the way and wasn't particularly more immersive than just doing it on the spot. I think the other editions also probably have something similar, but I haven't bothered to look, since it just seems like a bad idea in general to ever implement such a thing

>>51955365
Pretty much always this. It's quicker and the players don't have to run into town for two weeks and spend 1,000gpxlevel to level up.

>>51955465
>>51955500
Had a DM who rigidly enforced the time/money/training master rules for leveling in 3.5.

Result was players calculating the exact cash they'd need to advance during dungeons and modules. Then bugging out to the nearest town for 'muh nu powahz', even if it meant leaving time dependent tasks hanging, and spending multi-session spans of time searching out the trainers no matter how it fucked the mission.

Went ahead and added that to the list of rules to never add in my future games. Also quit playing with most of those people as soon as I could get something else going.

>>51955351
1e, 2e, and B/X required about 11 delves to gain 1 level.