Getting up at four o'clock every morning is sheer purgatory.

每天早上四点起床简直是活受罪。

《牛津词典》

I got up at four o'clock.

我四点钟起床。

youdao

Bring the children back from kindergarten at four o'clock.

下午四点把孩子们从幼儿园接回来。

youdao

She was nineteen. Those who knew Ida Tarbell in college say she would wake up at four o'clock in the morning to study.

VOA: special.2010.04.25

Mister Mindon looked at his watch. Four o'clock.

VOA: special.2010.05.29

Then, at four o'clock in the afternoon, twenty-four hours after the mortar fell on his friends and neighbors while they waited to buy bread, he will bend down and pick up his bow.

NPR: Excerpt: 'The Cellist Of Sarajevo'

Had you arrived from Mars at around four o'clock a couple of Saturdays back, you would have wondered what all the fuss was about.

BBC: Chick Young's view