A web app that works out how many seconds ago something happened. How hard can coding that be? Tom Scott explains how time twists and turns like a twisty-turny thing. It's not to be trifled with! https://twitter.com/computer\_phile This video was filmed and edited by Sean Riley. Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: http://bit.ly/bradychannels