I think I left mine (A4000D) on for 3 days at some point, trying to make sure it doesn't over heat. Now that it's very quiet, I'll be able to leave it on for longer
Currently looking into setting up a compiler and am going to attempt to compile some software that looks to be a bit out of date on the Amiga platform (namely perl, I'm going to be learning it soon, figured it'd be fun to do some of it on the Amiga!).
So at that point, I'm sure it'll be left on for longer periods of time

slaapliedje