What Day Is It, Really?

In this episode of "The Rest of Science," Professor Hannah Fry and Michael Stephens delve into the complexities of time and calendars, questioning the agreed-upon dates and exploring the history and science behind our modern Gregorian calendar. They discuss Pope Gregory XIII's calendar reform in 1582, the Julian calendar's inaccuracies, and the challenges of standardizing time across different regions and religions. The hosts also examine the Phantom Time Hypothesis, which posits that three centuries of history were fabricated, and explore the science of dendrochronology as evidence against this theory. They further discuss the arbitrary nature of the New Year's date, the importance of accurate timekeeping for navigation, and the transition from solar time to atomic clocks, highlighting the challenges of defining and measuring time, especially as we become an interplanetary species.