Summer begins on the longest day of the year.

夏天开始于一年中最长的一天。

youdao

After the longest day of travel so far, the bus rolls into Prague.

度过了到目前为止旅途上时间最漫长的一天，巴士开进了布拉格。

youdao

A picture taken with my trusty (and heavy) Pentax 6x7 at 10:30 in the evening on the longest day of the year.

一年中最长的一天，晚上十点半，我用我那很可靠的(也是很重的)宾得6x7相机拍下这张照片。

youdao

I always think of that wonderful scene in -- how many of you ever saw the Longest Day?

我总是想起那个绝妙的场景 --,多少人看过《最长的一日》

耶鲁公开课 - 古希腊历史简介课程节选

Tuesday will be the longest day of the year in the Northern Hemisphere.

NPR: Life in the Land of the Midnight Sun

Held each June on the closest weekend to the longest day of the year (this year from 22 to 24 June), midsummer is Finland's most enthusiastic party -- an excuse for lakeshore bonfires, midnight airshows, drinking games, skinny dipping, saunas and all-you-can-eat banquets of grillimakkara (grilled sausages) served with mustard and the season's first new potatoes.

BBC: Finland's summer feast

When he woke, it was already the next morning, the beginning of the longest day Max had ever known.

NEWYORKER: Max at Sea