Hi,
The timer in 16F84 is 8-bit, so it can count only up to 255. With a clock of 4MHz (1MIPS carryout), you can only have a delay of 256 microsecond. Prescale that to 256, and you get 65.5ms. So you need to check for the delay MANY times. It does not seem feasible.
So, I think you should use a software loop for the 8-hour delay.
If you use C or BASIC, the compiler should have delay functions, which can loop as many times as required.
Take a look at:
**broken link removed**
**broken link removed**
Hope this helps.
Tahmid.