It had been a twenty-hour day for the professor already.

It was five in the morning of a twenty-hour day.

Most of them had been pulling twenty-hour days since the first test flight and all that effort had finally paid off.

The episode was written in "a burst of twenty-hour days".

What we didn't have was enough people to do it alL You can only work so many twenty-hour days.

He hadn't worked twenty-hour days the last several months tracking her down simply to watch her disappear again.

I couldn't have survived the last couple of years, working twenty-hour days, with them squabbling around me all the time.

On Friday at three in the morning he was driving home after a twenty-hour day getting his new command ready for sea.

He'd been working twenty-hour days since obtaining his new position.