How long should lights stay on?

[Scuba Bob]

I have a 125G reef with 4X96W PC as the only lighting. Right now there is only a few leathers, mushrooms, and soft corals in the tank.

How long should I leave the lights on for each day?

I hear that the blues should come on before the whites. Is this true and if so how long before?

Is there a perfered time of day to have the lights on? i.e. Is it better to have them on it the morning or in the afternoon?

[grazhopr]

It's your preference. If you work, try to switch your lights on so that when you come back home you find your tank lit.
I would have those lights on for about 8-10 hrs. You might want to simulate dusk and dawn by switching on blues 1 hr earlier than the whites and switching blues off 1 hr later than whites.

[MontanaRocknReefer]

As grazhopr has said but I would leave the lights on for about 12 hrs a day as you have only 4 x 96ww of light on a large tank.