I would do this numerically instead of trying to make an analog or dedicated digital circuit. I mean that it would be simple to start with an AVR or PIC development board, perhaps like this one:
and then add outputs to control, well....what kind of output do you want. An image on a PC screen, some lamps or what? Anyway, you add the lamps or whatever to this development board. Then you code a simple program that supports an internal real time clock and modulates the lamp intensity using that clock and a calender table. You can use C, or Basic or other language to code the program, and you can build your own programmer for less than $10.