GPS Week Number Rollover – Microsoft has you covered!

In the late 1990s, the time and date features of computer systems became a topic of high interest for every business, as programmers realized that a simple abbreviation of four digit years to only the last two digits had a fatal flaw – the rollover to the year 2000. But early preparation and remediation ensured that the predicted Y2K disaster never occurred. In much the same way, Microsoft has completed preparations for the upcoming GPS Week Number Rollover to ensure that users of Microsoft time sources do not experience any impact.

In the financial services industry, coordinating and reporting time is critical. The same Global Positioning System (GPS) we rely upon daily to get from point A to point B, also provides precise and accurate Coordinated Universal Time (UTC) to financial markets. It transmits the correct date and time by supplying the receiver with the current week and the current number of seconds in the week. The week number is encoded into the data stream by a 10-bit field.  A binary 10-bit word can represent a maximum of 1,024 weeks (roughly19.7 years or an epoch). At the end of each epoch, the receiver resets the week number to zero and starts counting again. This is when a new epoch begins. GPS week zero started on January 6, 1980, and the second epoch will reset on April 6, 2019. Theoretically this could cause GPS receivers to malfunction. Since financial institutions worldwide use GPS to obtain precise time for setting internal clocks used to create financial transaction timestamps, malfunctions due to this GPS week rollover could affect the precise timing of trades for billions of financial transactions that happen each day. An inaccurate time stamp could result in non-compliance with regulations like the Financial Industry Regulatory Authority (FINRA) and the Markets in Financial Instruments Directive (MiFID II). 

Microsoft is aware of this upcoming transition and has reviewed devices and procedures to ensure readiness. Azure products and services that rely on GPS timing devices have received declaration of compliance with IS-GPS-200 from the device manufacturers, mitigating risk to users of Microsoft time sources.