GPS Rollover Week 2019: Everything You Need to Know

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If your organisation depends on accurate time, then mark the 6th April 2019 in your diary—it’s GPS rollover week.

On this day, the binary number that the GPS system uses to encode the time will reach its limit and tick over back to zero. If your hardware isn’t compatible, you could end up with unsynchronised systems and devices that think it’s years in the past.

Don’t worry, though, you might not need to take any action—it all depends on the type of GPS receiver you’re using. Even if you think you will have problems, the solution is as simple as upgrading your antenna.

Here’s everything you need to know to keep things ticking along in your business.

What is GPS Rollover Week?

All over the world, businesses, organisations and governments use time derived from the GPS system to timestamp their operations and synchronise their critical systems.

GPS Rollover and NTP time
GPS time is typically supplied to connected devices via an antenna and a time server.

The GPS system transmits the date and time as a 10-bit number that indicates the week and the number of seconds into that week. Your GPS receiver turns that into the day–month–year format you’re familiar with.

It’s a highly accurate system, but when the 10-bit number reaches its maximum—after 1,024 weeks, or 19.7 years—it ticks back over to the start.

The GPS system went live in 1980, meaning it rolled over for the first time in 1999, ending what was known as the first epoch of GPS time.

It will roll over again on the 6th April this year, bringing to an end the second epoch and causing problems for devices that aren’t ready for it.

What Should You Do About It?

If you depend on GPS time to coordinate your operations, timestamp your transactions or synchronise your processes, then you probably can’t afford to let those systems think it’s decades in the past.

Thankfully, users of Galleon Systems products have nothing to worry about.

The first thing to do is check which GPS receiver you’re using. If it’s a mushroom-style antenna, then you don’t need to do anything.  

GPS rollover week antennas
Mushroom antennas are already compatible with rollover week.

These newer antennas are fully compatible with GPS rollover week, meaning your critical processes will continue to run as normal.

However, if you’re using a box-style GPS antenna, then you need to take action.

These older receivers are no longer supplied or supported by Galleon Systems, and their compatibility with GPS rollover week is unconfirmed.

GPS Rollover and Network Time Servers
A box-style antenna will need to be upgraded.

To ensure your time-dependent systems continue to run as normal, you should upgrade your antenna now.

April 6th is fast approaching, but Galleon Systems can supply you with a mushroom antenna immediately, and our technical support department can provide any help you need to get it installed in time.

For more advice about GPS rollover week, contact Galleon Systems on

To order your mushroom antenna, contact


This post was written by:

Ben joined Galleon Systems as a copywriter in 2018. With previous experience of writing for a charity, he now assists in the production of Galleon articles, product pages and web copy.