Hello -=jugggernut=-.

  I've been working on a not too dissimilar project with ke Neehr
mailto:neehr@swipnet.se , so I can possibly help you with code.  You
might just ask him if he minds if I give you the code.

> 1. A certain website discuss about PIC 16F84 timer.  The 1 second
> delay well not be exactly 1 second because of the error.  How can I
> made an error correction with this?

  I'm not sure what sort of error you mean.  Care to explain?  I have
coded the clock to work with no error using a 4 MHz crystal.

> 2.Can I set an interrupt (ISR)? for the setting of the alarm time.

  You don't need *any* interrupts for this project.  Not only do you not
*need* them, you will find them a great hindrance.
-- 
  Cheers,
        Paul B.