somebody's/something's days are numbered
a person or thing will not continue to live, exist or be successful for much longer (指人)死期不远了,得意的日子屈指可数了;(指物)用不了多久了,寿命不长了

His days as leader of the party are numbered. 他作为党的领袖的日子已屈指可数了.



have had your day
to no longer be successful, powerful, etc. 得意之时已过;风光不再;日渐衰败

She's had her day as a supermodel. 她作为超级模特儿的辉煌日子已一去不复返.



it's not somebody's day
used when several unfortunate or unpleasant things happen on the same day 祸不单行;特别倒霉的一天

My car broke down and then I locked myself out─it's just not my day! 我的汽车抛锚了,我又没带房门钥匙---真是祸不单行!

one of those days
a day when there are a lot of mistakes and a lot of things go wrong 诸事不顺的日子;倒霉的日子

It's been one of those days! 这一天真倒霉!