They battled heroically for seven days and nights.

他们英勇地战斗了7昼夜。

《新英汉大辞典》

She missed the way it had protected her for seven days and nights.

她想念它使她有七日七夜免于遭受磨难。

youdao

For seven days and nights in succession, they hadn't eaten one grain of rice. They were so hungry that they couldn't get up from bed.

整整七天七夜，他们没有吃到一粒米饭，都饿得躺在床上起不来。

youdao

It took seven consecutive days and nights on trains to get from Moscow to Beijing, each day spent gazing out the windows for hours as the Siberian plains swept by.

BBC: How I quit my job to travel: The lawyer