Time and tide wait for no man.

The saying pairs time with tide and says that neither waits for anyone: both move on whether or not a person is ready. It uses that to warn against delay: an opportunity has its moment, and the person who hesitates or puts things off may find it has passed. Its lesson is to act while the chance is still there rather than wait for a more convenient time.

Among sayings about patience, it stands on the other side. It does not argue against patience in general, but against waiting when the delay itself costs the chance to act. It is misapplied as pressure to rush a decision that really needs time, or to a situation that waiting cannot spoil. Its force depends on telling apart a delay that only has to be endured from one that loses an opportunity.

It might be said to someone who is putting off a decision or an action that has a limited window, such as applying before a closing date, taking up an offer or settling a matter while the people involved are still available. It can work as a prompt or a gentle warning. It may land as unwelcome pressure when the person is delaying for a good reason, and as a reproach when it is said after a chance has already been missed.