You can refer this document Early or Late coming and generation OT by T555Z
You can change the HRS?0 in pcr ZE/L accordingly with your requirement.
1st comparing with 4 hours
then comparing with 2 hour, etc.
You need to have more knowledge in time schema, you can refer Useful documents for Schema & PCR configuration and press F1 key and using T-code PDSY more. Good luck!
Best Regards.
Woody (Trong Minh)