How do I add alarm to Digital web clock with JavaScript?

Question

Digital web clock

Answer 1

What kind of alarm you need?

You may add popup notification and/or sound using js, when is right hours.

But if user close window this wont work, maybe it could be done with cookies but i dont have experience with this.

To add alarm, for example when is some hour and minute like 9:30pm you should check current time if it match alarm time if so you may show notification or play sound.