Looking for an idiom

[TheShadow]

Hi, i heard an 'idiom/expression' on TV but i can't remember it

it was something in that context:

P1: I'm going to study at the library
P2: How long will it take / how long will you be gone? - are there any other synonyms with the same meaning which can help me find that idiom/expression

thanks

[BobK]

Those two are the obvious ones. An alternative is to put it in terms of the scene without them: 'How long do we have to manage without you?' or 'When can we expect you back?'. If there is only one of you (or only a few people) left you could ask 'How long have I/we go to hold the fort?'

b