ESMA just released guidelines that reinforce what was already clear in the MiFIDII regulation – that GPS time is a perfectly acceptable source of “traceable” time. There is a lot else that is of interest in this report, but it’s a good reminder to not be panicked by marketing scare-tactics.
As per Article 1 of the MiFIR RTS 25, systems that provide direct traceability to the UTC time issued and maintained by a timing centre listed in the BIPM Annual Report on Time Activities are considered as acceptable to record reportable events. The use of the time source of the U.S. Global Positioning System (GPS) or any other global navigation satellite system such as the Russian GLONASS or European Galileo satellite system when it becomes operational is also acceptable to record reportable events. GPS time is different to UTC. However, the GPS time message also includes an offset from UTC (the leap seconds) and this offset should be combined with the GPS timestamp to provide a UTC timestamp.