How to Switch Between two different Lights?

Projects General Guidance
10

Use the PowerSwitch Tail.
As far as programming, if you can turn on a led you can turn on a PowerSwitch Tail.

For time of day:
You would have to look into a RTC for setting the time if you want accuracy.
Or
You can use a light dependant resistor to get the relative time of day.

Try to write some sketches.
When you need help ask for it.