Sweetest Day is not a holiday that you hear much about. I know I had never heard of it until a couple of years ago. But according to http://www.sweetestday.com/:

Sweetest Day is celebrated each year on the third Saturday of October. Although often thought of by many as a second Valentine’s Day, Sweetest Day is actually a day meant to celebrate all the people who make your life special. It’s an occasion to make someone happy, a chance to celebrate and give gifts to relatives, friends, and associates.