Why hasn’t time been decimalised (part 2)

Simon Cains

High Wycombe, Buckinghamshire, UK

Astronomers and software engineers avoid all the complexity of calculating the time between two events in units of minutes, hours, days, months etc.

Instead, they calculate the Julian date by measuring the number of days and fraction of a day from noon on Monday 1 January 4713 BC – the beginning of the Julian period – for any event. So a typical recent date would have a Julian date of about 2.5 million, with enough decimals as required to specify the precise time.

I am writing this at Julian date 2459352.8548611. The calculation is fiendishly complex, but there are online tools to calculate the current Julian day and decimal.

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