Time delay in program

[LookingBeyond99]

How can I get my program to check something once every hour up to 12 hours in which case it would end. I want it to sleep in between checks as to limit excessive memory use. Is there a way to put the program to sleep or a good way that you guys know of to save memory during this process. Also what is the command to tell the program to check something after a certain amount of time. I just need a little direction then i'll be able to do it.

Thanks a lot!

 

[raider2001]

How about:

for (my $i=0; $i<=12; $i++) {
&do_something;
sleep(3600);
}