Seems like somebody might want such a thing.
Somebody might very well. I can see the appeal. And technically speaking, it shouldn't be too hard to produce. The hard part would probably be in getting the enterprise to pencil out.
OTOH there's always the good ol' real thing. For plant
growth, I run my lights about 9 hours a day, all year. But the animals
clearly know what season it is; my herp room has a window. (In all honesty, I'm certain the plants also know what time of year it is.) To make it perfectly clear for them all, I also turn off the supplemental heat in winter, allowing the room to go to ambient-basement temp (which is nice and cool). For what I keep (and what I keep is largely informed by what my living situation facilitates), all this is pretty fabulous. It's good for them, and it's good for me. Less battling the real world to create a likeness...
So I guess I would - as always - ask, "why?" For what problem, would this be an improved solution?
Don't take this as unfriendly - it isn't. It's just a straight question, without a sharp hard point to it. Providing an earnest answer could open a discussion, which seems your intent. (I am - as you are - unaware of the commercial availability of a timer such as you describe.)