Today is a red-letter day.

对于他们来说，今天是个好日子。

Today is real red letter day.

今天真是一个喜庆的日子。

Well it will be a red letter day.

嗯这将是一个红色的日子。

Today is a red letter day for us.

今天对我们来说是个值得庆祝的喜庆日子。

It was a real red letter day for you.

对你来说真是一个大喜的日子.

People are well dressed on red-letter day.

在喜庆的日子里，人们身著盛装。

October1 is a red-letter day for all the Chinese people.

十月一日是全中国人民的一个大喜日子。

Daniel:This is a red-letter day for you. Congratulations!

丹尼尔：今天是你的大日子。祝贺你哦！

A “red-letter day” is one of special importance and good fortune.

一个“大喜的日子（red-letter day）”是一个具有特殊的重要性和好运的日子。

It was a red-letter day for Ann when her first book got published.

安的第一本书出版的日子对于她来说是个值得纪念的日子。