To check if the LED strip and power supply work, directly connect your power supply's +12V to the +12V pin of the strip and power supply's ground to each R,G,B pin one at a time to see if they ...

Bucking the downward trend [HansLuijten] provides an astoundingly thorough set of LED strip patterns in his comprehensive post titled Arduino LED strip effects.

This is a where a Power Mosfet comes in. With the help of the Power Mosfet, we can use the low voltage output from the Arduino ports to control high voltage/current loads -the popular “12V LED strips” ...

All are held in place by a ring of hardware with spacers in them, and the RGB LED strip that is used to display time and date wraps around those spacers.