Can you provide a little more detail on what you're trying to do?
Rules are triggered immediately by specific user actions (such as creating, updating or deleting a node), so typically you wouldn't need a condition of that nature, since the rule would always fire well within 24 hours of the event occurring.
If you're trying to run a periodic scheduled job of some kind, rules aren't really appropriate - timed activities such as this are typically implemented using Quartz jobs.
Cheers,
Peter