The No Pants Day, an international phenomenon, encourages people to travel in their undergarments.
It happens only once a year -- when they all dress up and step out of their homes, but sans their pants.
The No Pants on the Subway is an annual ritual where travellers take the tube without wearing pants and pretend like it's no big deal.
The event kick-started way back in 2002 in New York and has since caught the fancy of several countries including the UK.
Think we're joking? Take a look at these pictures!
Here's a picture from London underground.
Photograph: Paul Hackett/Reuters
Men and women flaunt their bare thighs in Vienna, Austria.
Photograph: Heinz-Peter Bader/Reuters
Meanwhile, in Berlin, a young couple showed off their goofy side.
Photograph: Hannibal Hanschke/Reuters
It's all in the family! In Berlin, here, a mother encourages her son to take part in the event.
Photograph: Hannibal Hanschke/Reuters
Now that's taking daring to an altogether different level! Don't you think so?
Photograph: Hannibal Hanschke/Reuters
New Yorkers join in to show their love!
Photograph: Stephanie Keith/Reuters
This is how London tubers stepped out on No Pants Day!
Would you dare to do this? Tell us!
Photograph: Paul Hackett/Reuters