Working Naked Day first started in 2010 by Lisa Kanarek, she is a business consultant who wanted to dedicate Working Naked Day to those who work from home, to help them feel free and relaxed. It is celebrated by those who don't have to go in to the office and put up with a boss giving you grief.
This holiday isn't officially recognised, however over the last few years, it has caught on quickly with the home-based workers. If you work from home, and year reading this thinking 'that's ridiculous', all I can say to you is it's only one day a year, why not just do it!
As February is a cold time of the year, I would personally advise a blanket, or having the heating turned up to the max!