'This business of thirty-hour days and seven-month pregnancies!'

In a few minutes the puppeteer had reset the timer to a thirty-hour day, and cut the current by half.

Proxima had a thirty-hour day.

One hundred sixty-five of the Ringworld's thirty-hour days.

Their planet seems to have about a thirty-hour day and I have no idea what their year might be.

Not even after hundreds of years had the human metabolism managed to adjust itself to the thirty-hour day, the fifteen-hour night.

But it was right, he'd counted one hundred fifty-one thirty-hour days.

So Lisele's best guess was that during one of Sitdown's thirty-hour days, communication between ship and scout could be no more than six two-way exchanges.

Like it or not, we have to adapt to this planet's thirty-hour day.

Maybe her period was due to start; with these thirty-hour days, she d lost track.