MIKES, the centre for metrology and accreditation of Finland, has connected the Metsähovi Geodetic Research Station to the official time of Finland, UTC[MIKE]

Some quotes from the article Metsähovi connected to the official time of Finland:

The time transfer to Metsähovi, Kirkkonummi, occurs from the UTC-laboratory at VTT MIKES Metrology in Otaniemi via optical fibre using the White Rabbit protocol. VTT MIKES Metrology has been an early adopter of the White Rabbit technology for time transfer across long distances. White Rabbit was developed at CERN, the European Organization for Nuclear Research.

The measurements show, for example, how the travel time of light each way in a 50-kilometre fibre optic cable varies by approx. 7 nanoseconds within a 24-hour period as temperature changes affect the properties of the fibre optic cable, particularly its length.

The uncertainty of time transfer is expected to be 100 ps or better. The precision of frequency transfer is currently approx. 15 digits.

Note that the image in the article shows also the High performance 8-channel Pulse and Frequency distribution amplifier that Anders Wallin from MIKES designed and made available as Open Hardware.