Best Practise help: Automation using 8 step timers to control 4 climate entities

I have a concept I want to achieve but I cant quite get it in my head how to do it. YAML ok and templates ok. Concepts are most welcome.

I need 8 timers (hours) controlled by individual input numbers in the frontend and each timer has a temperature associated with it. These steps can be applied to any of 4 Climate entities.
eg:
CLIMATE1~4
STEP 1: 18h @18degC (input_number.time1) @ (input_number.temperature1)
STEP 2: 24h @19degC (input_number.time2) @ (input_number.temperature2)
STEP 3: 48h @20degC (input_number.time3) @ (input_number.temperature3)
STEP 4: etc…
STEP 5: etc…
…8: etc (input_number.time8) @ (input_number.temperature8)

Each timer will change the temp on ANY of 4 different climate entities.

The automation MUST be able to survive a reboot and MUST resume each climate entity (4 different) where it left off once back online.

Within the ecosystem - I cant seem to work it out (roughly) how to do a best practise

Any help with a seed of thought is REALLY appreciated.