Question: When we first realised there was time how did we know what time it was?

Hazel Gibson answered on 5 Mar 2018:

Haha brilliant question – I love questions about time, particularly because as a geologist it was important to me for much of my studies. I think the thing to remember is that humans have been messing with time for thousands of years, so it’s difficult to work out who would have been the first person to work out what time it is (I also love the idea of some little person working away in a hut and suddenly going ‘of course, it 2.32pm!”). Basically the way we use time is defined by the way the planet moves around the sun and the way it rotates, which it has taken us until very recently to properly figure out.

Interestingly that has also been changing throughout our planet’s history! In the Cretaceous Period, when the dinosaurs were alive, there were fewer hours in the day (because the Earth rotated faster), but also more days in the year! In terms of time itself humans have used many methods to measure the time, from sun dials to water clocks, but it is unlikely that any of these were regulated until very recently. So it could have been 2 hours past midday for you, but 1 1/2 hours past midday for someone else. Also a lot of time was dependent on you setting the measurement going, like lighting a candle with measurements of time on it, or winding a pocket watch, and as such were very unreliable.