All short call reserves are two hours from notification to airport report. If you are flying a flight you have an hour from that to push. If you are deadheading, your report time will be 1/2 hour before push.

Flying: You must be able to push in 3 hours from notification. So get a call at 0827, then you have to report no earlier than 1027 and have to be able to push no earlier than 1127.

Deadheading: You have 2 1/2 hours from notification to push. Get a call with a DH first leg at 0827, still have a 1027 show with a push of 1057 at the earliest.

Make sense?