"In the beginning, the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move." If you know where that quote comes from, then this event is for you! And if you don't know where that line comes from, then you need to read one of the best books ever written as soon as possible! Of course, this quote doesn't come from the first book, but once you read the first one, then you are going to definitely want to read the rest. Towel Day every year is May 25th and celebrates all the best parts of The Hitchhikers Guide to the Galaxy. And the Perth Observatory is hosting a Towel Day Night Tour which promises to excite even Marvin the paranoid android.