I want one switch to power two light fixtures.
Once the switch is flipped, I want light A to start off bright and gradually dim down till it is off and vice versa for light B.
Once A is minimized and B is at max brightness, I want them to gradually go back to their original brightness.
This cycle should continue, until the power is switched off.
How can this be accomplished while controlling how long it take for the dimming/brightening cycle to complete?

I have been looking around for an answer with no luck so far, but the group here seemed capable of answering the question.

 

If I were to do it I would use the idea based on fig 3 in the Fairchild AN-3006 and use a small single 8pin Picmicro in place of the 555's.

 

an anti-phase triangle - the higher the frequency the greater the level "hitting" error - a simulation - the reset to can be achieved by going the integration fast until your startup condition is reached - then - turn on the lights and reduce speed to "normal" or "default"