GPS week and seconds to date converter
GPS receivers and navigation logs record time as a week and seconds since 6 January 1980. Enter them here to get UTC.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter gps week, seconds of week, 1024-week rollovers to add (10-bit weeks) and time zone (optional).
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
GPS seconds = (week + 1024 × rollovers) × 604800 + seconds of week. UTC = 1980-01-06 00:00:00 + GPS seconds - leap seconds (18 since 2017).
Example
Inputs: GPS week = 2,438, Seconds of week = 345,618, 1024-week rollovers to add (10-bit weeks) = 0, Time zone (optional) = UTC. Result: Date and time (UTC): 2026-10-01 00:00:00; Weekday: Thursday; GPS minus UTC (leap seconds): 18.
Limits and caveats
- The leap second table runs to 2016-12-31, and none has been added since as of 2026. If a new one is announced, later results will be one second off.
- During a leap second itself the time shows 23:59:59 twice.
Questions about this tool
Why is GPS time 18 seconds ahead of UTC?
GPS does not add leap seconds, while UTC has added 18 since 1980. The converter removes them automatically.
What is a GPS week rollover?
The legacy signal sends the week number in 10 bits, so it wraps to 0 every 1024 weeks. Rollovers happened on 1999-08-22 and 2019-04-07.
How many rollovers should I add?
If your device shows a week below 1024 for a recent date, add 2 rollovers for dates from April 2019 to November 2038.