annually on February 27th (since 1996)
Adrienne Sioux Koopersmith in August 1995
A "no-brainer" is something that is simple and easy to figure out, or obvious and logical. The phrase started as engineering jargon, became popular in 1990s and 2000s, and is now common in business environments. The day is for doing "no-brainer" activities—for doing things that are easy and obvious. Conversely, the day is not for doing things that require a lot of thinking and study. The day was created by "America's Premier Eventologist," Adrienne Sioux Koopersmith.
How to Observe
Celebrate the day by only doing things that require little thinking! This is not a day for hard mental work; this is a day for letting your mind relax. You could also spend the day by using the phrase, "That's a no-brainer!" I didn't need to tell you that though, that's a no-brainer!