EpochLab

GPS Time Converter

Convert GPS time to UTC

GPS seconds, week number and time-of-week, converted with the leap-second offset applied — because GPS time has taken none since 1980 and is now 18 seconds ahead of UTC.

How this is worked out

  • The leap-second table runs from 1980 and is current to the last announcement; no leap second has been added since the end of 2016.

Questions people ask

The things that come up about gps time converters, answered plainly.

Why is GPS time ahead of UTC?

Because it does not take leap seconds. GPS time started aligned with UTC on 6 January 1980; UTC has added 18 seconds since, so GPS time now runs 18 seconds ahead. A receiver reporting raw GPS seconds is not reporting UTC.

What is the week number rollover?

The GPS signal carries a 10-bit week counter, so it wraps every 1,024 weeks — about 19.6 years. It rolled over in 1999 and again in April 2019, and older receivers that did not handle it jumped back two decades. The page shows when the next one falls.

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