how to age your christmas lights Why? It is important to keep track of the age of your Christmas lights sets. Older lights are more prone to failure. By knowing the age of your lights; you can put the older ones in less visible areas and you will be able to replace the oldest lights with new ones as they near the end of their life cycle. How? Simply attach a 4" zip tie to the cord, just in front of the male plug. Each year after you remove the lights, add the next color zip tie.
         
Color:

Example:

Years:
Black

1 Year
Yellow

2 Years
Blue

3 Years
Red

4 Years
Green

5 Years
Brown

6 Years
White

7 Years