time clauses with will

[atabitaraf]

1. Until when will you stay at the office?
2. Until when do you stay at the office?

I think both are natural but I read in time clauses we are not allowed to use will after when.

[bhaisahab]

1. Until when will you stay at the office?
2. Until when do you stay at the office?

I think both are natural but I read in time clauses we are not allowed to use will after when.

They are both OK in the right context.

[Barb_D]

Personally, a lot more natural to me is:
"How late" not "Until when"