[HELP] 23:59:59 countdown 7 segment display using 74192 ic

hi guys can any one help me, how to make a countdown clock timer..
from 23 hrs 59 mins 59 sec to 00 hrs 00 min 00 sec
using any 74192 IC.. schematic can help me.. plz..
thanks in advanced!

It will take 6 of the 74192's. 2 for the 60 seconds counter, 2 for the 60 minutes counter and 2 for th 24 hours counter. Then you will need a 1 second clock, and if you want a display you will need decoder drivers and displays.

i have the 7 segment display, and 6 74192, my problem is how can i make a 23:59:59 display from the start can you teach me..