往日的英文：
in former days

参考例句：

auld lang syne
【苏格兰】旧日;美好的往日。

Songs can evoke old memories.
歌曲可以唤起往日的回忆。

It's a tradition to sing `Auld Lang Syne' on New Year's Eve.
在除夕唱｀美好的往日＇是传统风俗.

We frequented that coffee shop in bygone days.
往日我们经常光顾那个咖啡店。

We'll take a cup of kindness yet, for auld lang syne.
我们应当为这往日的友谊干杯。

Singapore had just emerged relatively unscathed from the Asian economic crisis and the market was booming again.
此时的新加坡刚从波及全亚洲的经济危机中走出来，市场又恢复了往日的繁荣。

There was a busy, bustling, disputatious tone about it, instead of the accustomed phlegm and drowsy tranquility
他们都带着一种忙碌、慌乱，好争论的神气，一点也不象往日那样心平气和并且保持着昏沉沉的宁静。

Slough off old prejudices
丢掉往日的成见

The fighter pilot seems to be losing his dash.
战斗机飞行员似乎已经没有了往日的风光。

Experience again or reproduce(past emotions,etc)
再次经历、体验或产生(往日的情感等)

former是什么意思：
n. 形成者，模型
adj. 过去的，在前的，以前的，昔日的
pron. 前者

Without the latter, the former is of no avial.
没有后者，前者是无效的。

The former is a painter and the latter is a composer.
前者是一名画家，而后者是一名作曲家。

He was a former divinity student.
他以前是一个神学院的学生。

He is a former England international.
他是一名前英格兰国手。

This is a former palace built by the Portuguese.
这是以前葡萄牙人修建的宫殿。

days是什么意思：
n. 一天；白昼，白天；工作日；时代，时期

Things go on day by day.
事情逐日进行着。

Day by day the situation is improving.
情况在一天天地好转。

Like this, day after day.
就这样，日复一日。

It was a fateful day.
那是个不祥的日子。

Meantime, from day to day they endure.
同时，一天天他们捱了下去。