Anneloes Opperhuizen and Marijke Gordijn, founder of Sleep in Sync and owner of Chrono@Work, have written a book together about the biological clock. The biological clock determines when it is a good or bad time to exercise, think, sleep, eat and much more. It also determines who is a morning person and who is an evening person. In the book The Clock with a Thousand Hands, they explain what the biological clock is, how it works, where it is in our body and what it does. But also why we get sick if we don’t listen to the clock. What is the best way to listen and what can you do if that doesn’t work out so well?