(1) All night long: 整夜 Some stores stay open all night long.

(2) Call it a day: 一天工作完毕 We have class from 9am and will call it a day at 4.30pm.

(3) Day after day: 每天 It is boring to do the same things in school day after day.

(4)Day in day out: 一天又一天 Henry wears the same old jeans day in day out.

(5)For a rainy day: 为困难的日子作准备 When a person gets older, he will realize the importance of saving for a rainy day.

(6)In this day and age: 在现在这时代 In this day and age, no one can expect to get something out of nothing.

(7)Have an off day: 不大成功或顺利的一天
Tom did not do well in yesterday's test. He considered him unlucky enough to have an offday.

(8)The order of the day: 一般的惯例
In a petroleum station here, payment by credit card is the order of the day.

(9)The other day: 几天前 I bumped into an old friend the other day.

(10)To this day: （指日期）准确地 It is 40 years to this day that I left university.

(11)Have seen better days: 曾经历过好日子
Jack was an office head in that university before he came here. He has seen better days.

(12)Some day: 将来 Everyone hopes to be great some day.

(13) One's days are numbered: 末日将临：
Under computerization, unskilled workers become redundant. Their days in a company arenumbered.