In many industries, it is critical to time information transfers accurately and traceably to a calibrated time reference. This includes the financial sector, air travel and the energy sector, for example.
In the fall of 2022, DFM established Denmark’s first official representation of UTC called UTC(DFM), which from March 26, 2023 is the basis for official time in Denmark. Since then, DFM offers you the possibility to synchronize your device to UTC(DFM) at time.dfm.dk. The advantage of syncing your device to a local time server in Denmark over a foreign one is that the accuracy is much better. When time.dfm.dk is used as a time source, you get a trackable time on your device with an accuracy that is essentially only limited by the time internet data takes to travel to DFM’s server and back to you: The package’s so-called “roundtrip delay”. In Denmark, roundtrip delay is typically less than 1 millisecond.
Synchronization is done using Network Time Protocol (NTP) or Network Time Security (NTS), which are standardized international internet protocols for transferring time information between devices and time servers. NTP is the basic protocol that uses timestamps of the packets exchanged between a device and the time server over the internet to measure roundtrip delay and clock offset (time difference between device and server). This information can be used to correct your device’s system time to match the time reference and to guarantee a maximum error on the time indication. NTS adds a layer of security to the NTP protocol by using TSL/SSL encryption to ensure data integrity and authenticity control of DFM time information.
Of course, it is important that the time reference itself is accurate. As the DFM time server is directly connected to our atomic clock, the time server clock follows UTC(DFM) with an accuracy of less than 20 ns, guaranteeing traceability to the coordinated world time UTC, which is calculated by BIPM(https://www.bipm.org/) as the average of over 400 atomic clocks at 69 international metrology institutes and research laboratories.
On the DFM website https://dfm.dk/ntp/ you can find short guides on how to synchronize your device to UTC(DFM) for a number of the most common operating systems.