Accurate and precise time will be almost universally necessary for science experiments. This requires a reference standard and the distribution of a time signal across the seafloor network. In the US, the reference function is performed by the National Institute for Standards (NIST), who provide standard time which is distributed through the global positioning system (GPS) satellites. For NEPTUNE, high accuracy time from the GPS system will be distributed over the low level control fibers using a straightforward addition to the SAIL protocol. This allows high accuracy time to be transferred from the shore station to the nodes including correction for propagation delays on the backbone cable, and will provide synoptic time ticks everywhere on NEPTUNE. The accuracy goal of 1 s is readily achievable.