till/until all hours

until all hours

Fig. until very late. Mary is out until all hours, night after night. If I'm up until all hours two nights in a row, I'm just exhausted.
See also: all, hour, until

till (or to) all hours

till very late. informal
See also: all, hour, till

till/until ˈall hours

until very late at night or early next morning: She sat up till all hours trying to finish her essay.
See also: all, hour, till, until