I started my new job in Jan and it became immediately apparent that late nights are normal here.
Now, I don't mind the occasional late night when you've got something to do or the shit has hit the fan. Let's say I'd even volunteer to do, say, 2 all nighters a month. The culture here though is to only think about going home at 7pm, and regular impromptu late working. For example, at 5pm today I was told I need to stay "for hours" to work on something I shouldn't really have to work on and it now looks like I'll be here until 11ish.
It stems from poor management higher up (who all leave at 5 incidentally) and given that I get no extra pay, time off in lieu and am not particularly well paid in the first place, I don't really want to work here any more. It's wrecking my home life as I can't make any plans in the week and am always grumpy outside of work.
How long should I stay here for? How do you tell new employers in an interview why you left without looking workshy?

