Time Converter

Convert between seconds, minutes, hours, days, and years, with why time units aren’t based on ten explained.

Why Time Refuses to Follow the Metric System

Every other major measurement category eventually standardized around clean base-ten relationships, but time units stubbornly kept their ancient, irregular ratios, sixty seconds to a minute, sixty minutes to an hour, twenty-four hours to a day, because they trace back to Babylonian and Egyptian astronomical systems built on the number sixty and on observed divisions of the sky and calendar, long predating the metric system’s eighteenth-century creation. Sixty was chosen by ancient mathematicians specifically because it divides evenly by so many numbers, two, three, four, five, six, ten, twelve, fifteen, twenty, and thirty, making it genuinely convenient for splitting time into halves, thirds, and quarters without leftover fractions, a practical advantage that likely explains why it survived every later attempt to decimalize time, including a serious French Revolutionary effort to introduce ten-hour days that never caught on. The year itself introduces its own irregularity, since Earth’s orbit doesn’t divide evenly into whole days, taking approximately 365.24 days, which is exactly why leap years exist, adding an extra day roughly every four years to keep the calendar synchronized with the actual astronomical year rather than slowly drifting out of alignment with the seasons over centuries.