Set timer for certain processes?

Hello,

I am working on a project involving simulating a heat pump and its defrost cycles. I am currently struggling to set time for the defrost operations. For example, I want the defrost cycle to start 5400 seconds after certain conditions have been met, and I want the defrosting to continue for 300 seconds and then to stop and allow for a normal heat pump work.

What block(s) do I need to use to implement this?

I have tried searching online for a while, but I did not find much. I started using simulink recently. Your help and advice will be very much appreciated!

Thank you in advance!

Kind regards,

George