Date and time

I'm doing an application in php ,online exam.The exam shud be submitted within a given time.How to do this using Java script.

It depends. It would be bad doing it in JavaScript, as it can be turned off, therefore it could be submitted anytime.

Question: how is the exam submitted?

Tell us the sequence of operations to submit the exam

Better in php (according to the server's time) as javascript return's the client's time, so that the candidadate can simply modify the computer's clock to earn some extratime...