No Pants Day

I have never heard about this in my life. While checking some news out I came across this article. No Pants Day, it is getting quite popular these days and everywhere around the world this is happening. It must be so cold outside walking around in underwear all day. Don`t know if I can actually stand the cold in my underwear. The funny part to this is that when restaurants have signs that read, No Shoes, No Shirt, No Service. They don`t ever say anything about No Pants. So it makes me wonder about all the people going to have some food. Is everybody that wears underwear only, not allowed in the restaurant? How does this work out?