Hi Carlos!
It should work, I think!!!

Maybe I am wrong, maybe someone doesn't agree with me, but... First, about your code. Code, in my opinion, is more readable, when you show all positions of interrupt's vector table. For example:

ORG 0
JMP After_Reset

ORG 1B
JMP Timer_1_Interrupt

You can also show unused vectors as ORG.. & RETI. When you back to the program, it is easy to recognize what is your code doing, which interrupts you've been using etc. And it is easy to show someone to get advices.

I see in your code, that you are starting timer 1 before variables of HOURS, MINUTES, SECONDS and TICKS setting. Yes, of course, you are switching timer 1 interrupt on after setting variables, but I think good behavior is to set variables then start timers and interrupts. It can prevent you from troubles in the future.

Good luck!
Jacek