These days they were up at the crack of dawn.

这些天他们在破晓时就起床。

《柯林斯英汉双解大词典》

Dawn broke at 4.45am with the Muezzins calling the faithful to prayer; and for two successive days this was my signal to get out of bed and try to get as far as possible before the rush hour began.

在破晓时分的4：45分，宣礼塔就开始召唤虔诚的信徒祷告。这连续两天成为叫我起床的信号，这样我能在交通繁忙时刻到来以前尽可能多赶路。

youdao

Let me repeat that: we create as much information in two days now as we did from the dawn of man through 2003.

让我强调一次：如今我们每两天所创造出来的信息就有2003年以前(从文明开始)创造的所有信息一样多。

youdao

The anniversary celebration is called "Ten Days of Dawn."

VOA: special.2009.02.07

Three days later, Feiler awoke before dawn with a big idea: he would assemble a group of trusted men to serve as surrogate fathers after his death.

VOA: standard.2010.06.19

The working day began at 8am, the crack of dawn for investment bankers in those days.

ECONOMIST: Siegmund Warburg

At the dawn of e-commerce, many claimed the days of the brick-and-mortar retailers were numbered.

FORBES: How E-commerce Has Remodeled Offline Stores

Earlier this year I wrote a story for CMO.com titled How To Rein In The Riches Of Big Data which dealt with the fact that according to a 2011 IBM study of more than 1, 700 chief marketers worldwide, consumers now create as much information every two days as they did from the dawn of civilization to 2003.

FORBES: Forget About Big Data, Some Marketers Don't Even Collect Name And Address