Another Gardening Project - Light Scheduler

Hi Guys! Im building kind of a gardening project. My idea is make a Hydoponics controller, apart from controlling things like Ph, ec and other values I need to, in some way, manage the vegetative times and then the flowering time.

For example, when seed is planted the system should take care of all the rest, by saying this I mean that the light times should be controlled automatically, i.e : the first 3 month the program will have to set vegetative light times and after those 3 month the flowering light times comes.

Any advice how can i achieve this?

Thanks in advance!