generally 24 hours after the bad weather ends all flights are back to normal. This storm is very different - because it covered such a large swath of the us, many many more planes and crews are stranded in the wrong cities than from a typical storm (in addition to major airport delays due to lack of personnel). Delta ops told me last night not to expect normalcy until sunday. and I heard similar wishy washy "hopefully saturday" from jblue last night which sounded a lot like sunday as well. cant speak about other airlines but I would assume they are in similar saturday/sunday situations