What does it mean that shoebox lights are on a timer, but also have a photocell that turns them on automatically if it gets dark earlier due to a storm, rain, cloudy day, etc?

Is there a switch where you can either use the photocell or timer feature...dusk to dawn or come on the same time every night regardless if it gets dark sooner or still light out?

There is a shopping center near me that has shoe box lighting in their parking lot. They have sodium lamps that give off a orange glow. When it gets dark due to a storm, they come on, but when the storm passes and it gets lighter again, they turn back off.

It is possible to connect an outdoor lighting to a photocell and a timer for energy saving, so that the lamps will turned on at dusk and turned off again at midnight or at the late evening for energy saving.
There are several parks and sports fields in Israel, that their floodlights turns on with the streetlighting, by the controller of the streetlighting, but turns off seperately at 21:00-23:00 by a seperate timer for energy saving.
The streetlighting control in several cities and locations in Israel (Haifa, Nesher, the ports of Haifa and Jerusalem), is done by computer based controllers that remotely controlled by a PC with Windows XP and Wizcon or other software. I don't know if there are other cities in the world, that uses a computer to control their streetlighting.

Usually the PC and timer would go in series (PC output to timer switch contacts, but timer motor is running all the time). This allows to switch on by brightness and switch off by time

Sometimes different logic is implemented though, basically everything that can be done wih some relays is to be expected

If you design such a system, be aware of this : Most photocells switch on immediately when power is applied, then after set up they switch off if it is day. So if the photocell is getting power from the timer outout then the lamps will start 2 times every day (first time for a minue or so and go off again), so wear faster. But you may be fine with doubling the startup show ^_^