the 5th of May is the kid's day.
We used to take our kids to the theme park, like Everland, Lotte world, Seoul park land or indoor of film theater if it's rain.
When I was young, I was taken to the film theater and my mom bought me the Jah-jang-myun(Chinese noodle) what was the most popular dishes for kids in my age.
And also no spanking, no penalty, for the kids by his or her parents.

I think this is the day for under K-6, I mean by elementary schooler.
We, Korean parents were too busy to play or to take care of their kids, so Mr.Bang, jung-hwan proposed to designated a day for kids in the 1930 or 1940's.
I doubt that still we need these kind of day for kids, and actually this is one of the controversial agenda when we discuss about excessive national holidays.

Tips;
1. Keep away from the amusement park and express way.
2. Buy something for kids(doesn't matter how musch is it) if any chances to meet.
3. Look around, if any kids near You left alone...
jz