Multiple cities have signed on to celebrate “Foursquare Day” on April 16th, but none as prominently as New York City. NYC Mayor Michael Bloomberg has declared April 16th “Foursquare Day” in New York City to celebrate the company and its success — but also to attract new startups to the area. “There is no better place than New York City to start a business,” Bloomberg’s office said. “We are the most exciting and most dynamic place on the market, an international capital of the arts, fashion, and finance. With Foursquare leading the way, we look forward to this generation’s innovators and entrepreneurs making their mark on our City in the years to come.” Foursquare was founded in New York City in 2007 by co-founders Dennis Crowley and Naveen Selvadurai, and the company currently keeps its headquarters there. The social network says it has over 8 million users worldwide and adds roughly 35,000 users each day. If you haven’t tried it yet yet, you’re not too late. The latest version launched early last month and added a ton of useful features, including better specials. Oh, and if you’re wondering why Bloomberg chose the 16th specifically, it’s because four squared is 16 (and April is the fourth month).