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Episode details

World Service,21 Dec 1999,23 mins

Measuring time

Discovery

Available for over a year

A look at time; how we measure minutes, weeks, months and years. The first calenders date back to the Stone Age, and man has long been obsessed with making sure he can keep track of time. The earth's orbit of the Sun is not exactly 365 days, so a calender was made to introduce a leap day every four years, but even that isn't exact.

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