A normally unreliable person or instrument can occasionally provide correct information, even if only by accident.

Apples are healthy and stave off illnesses. / Healthy eating prevents illness.

Alternative form of don't give up your day job

Alternative form of a stopped clock is right twice a day

There is no need to worry about the future; the present provides enough to worry about.

(idiomatic) used to hurry people up

Alternative form of every dog has its day

September 19, a humorous holiday during which observers are supposed to talk like pirates.

Alternative form of don't give up your day job

Used to say that you want someone to do something faster because you do not have enough time to wait for them to finish