Bad hair day: a day on which everything seems to go wrong
“头发糟糕的日子”，暗示一整天都不顺利，心情不好，很不顺利的一天；倒霉的一天
Cold day in hell: An impossible event used as an analogy for something the speaker thinks will never happen
某事不可能会发生
It will be a cold day in Hell when I let you borrow my car!
Good deed of the day: Some especially good, kind, or generous thing one has done. 行善日
Sometimes used ironically or sarcastically to suggest that a certain deed is not good or not as good as someone thinks.
Lucky day 幸运日
Plain as day 非常明显，明明白白
A broken clock is right twice a day 即使是坏掉的钟每天也会有两次准的时候，比喻经常错的人也会有对的时候
One’s day in court 得到申辩的机会
to get an opportunity to give your opinion on something or to explain your actions after they have been criticized
Rome wasn’t built in a day 罗马不是一天建成的。
Don’t give up your day job 别浪费时间了。做好眼下的工作，不要追求不可能成功的事情。
