This might be a stupid question but is their a limit like on eoc or can i bot overnight?

There is no limit as to how long you can run the bot.

you will auto logg after 6 hours

yes there is

First of all, there is a limit, but it can be bypassed.

But what you should really be considering is the amounth of randoms you can get in that timeframe. Unless you're e.g. alching in a place where randoms don't come, you won't be very safe botting overnight with the current system. I personally babysit my bot and do other things (e.g. make music, do some cleaning, reading etc.) at the same time so you don't really lose time.

For the moment I think that might be a lot safer than leaving it on over night