The ability to synchronize remote clocks plays an important role in our infrastructure, from maintaining coherence in the electrical grid to allowing precise positioning and navigation. 

However, the signals used to transfer timing information can be spoofed by an adversary with classical time sychronisation protocols.

Here we propose a protocol that builds on techniques from quantum communication to provide a verified and secure time synchronization protocol. 

The absolute offset between two clocks can also be determined without assuming any knowledge about the propogation time of the signal used for synchronisation. We present initial experimental data that demonstrates this aspect of the protocol.