机不可失时不再来

机不可失，时不再来

Literally means:

don't let slip an opportunity or it may never come again

Actually means:

opportunity knocks but once

机 in Chinese means opportunities, which is a valuable and favorable chance. 时 in Chinese means a favorable occasion, like the moment of high tide, which appears only at a certain time.

This phrase is often used to remind people that opportunities do not come often, so one must take a firm grasp of any opportunity and never let pass.

机，机会，即难得的有利的时间；时，时机，即在某一时间才有的有利条件。

机不可失，时不再来，指机会难得，定要抓住，一旦错过，就不可能再回来了。多用来提醒人们注意:机会不是经常有的，一旦来了就要牢牢抓住，不可丢失。