LH778 was delayed for 11h last night. Writing this message above 36000ft now after uneventful and successful departure.

But I'd like to ask the audience - what was the longest delay you've experienced and how it was handled?

Let's not consider cases when you are flying out from a remote island in South Pacific which has one flight in a week or case like hurricane Katrina or ongoing civil war outside the airport.

So, fairly ordinary/developed places/airports. Also let's exclude cases when the flight was canceled or you've been rebooked to another flight.