You'll either want to avoid Washington Square Park on April 1, or you'll want to make sure you're there at 3 p.m., armed with pillows.
The date marks International Pillow Fight Day, which is celebrated annually in cities around the world. Communities gather together to beat each other with pillows. Plus, it's an excuse to wear pajamas during the day.
Before heading into the feathery fight, take note of these rules: Use soft pillows and don't hit anyone without a pillow!
The event is open to all ages and is free to attend.
International Pillow Fight Day: Philly
Saturday, April 1
Beginning at 3 p.m. | Free
Washington Square Park