Unless you're Jewish, there's a pretty long stretch of non-holiday time between Labor Day and Halloween (and let's face it: you're probably not Jewish). I assume our forefathers--gentiles all--had this boring stretch of calendar in mind when they invented Columbus Day out of thin air.
But we need something good.
I envision a day where you go home to spend some quality time with your parents. First you listen to your dad complain about local newscasters, stoplights, and companies who outsource customer service hotlines to India. Then he reminds you to shut the refrigerator door all the way. Later your mom chimes in about what a good speller you were in third grade and wonders aloud if she'll ever get to meet a single god damned grandkid. The festivities culminate in a relaxing dinner at a Mexican restaurant, where the whole family takes turns questioning Virginia Tech's offensive play calling.
We'll call it Belabor Day. The first Monday in October after the last Sunday in September sounds about right.