As with so much that’s great and terrible about modern pop culture, Star Wars started it all. A clever pun with ties to Margaret Thatcher (read on) gradually evolved into the theme for a made-up holiday now celebrated with at least as much passion as many “real” ones—like Labor Day, it’s really the sales that get…
Source: LifeHacker – May the Fourth, Rex Manning Day, and 10 More Made-Up Movie and TV Holidays