Time is a fundamental part of our universe, but how we divide it up is man made. Who invented time as we know it, and why does it matter? "Subscribe to Earth Science for more fascinating science videos - http://bit.ly/SubscribeToEarthLab All the best Earth Science videos http://bit.ly/EarthLabOriginals Best of BBC Earth videos http://bit.ly/TheBestOfBBCEarthVideos Here at BBC Earth Science we answer all your curious questions about science in the world around you. If there’s a question you have that we haven’t yet answered or an experiment you’d like us to try let us know in the comments on any of our videos and it could be answered by one of our Earth Science experts. "