Not built-in, no. Reason being, you can't really sync network time and have it be the same on all clients due to latency -- and if you use Network.Time in Unity, you will see exactly that problem. Gave me quite a few "wtf" moments in the past, actually.
If you really want to sync game time, do it on the host (TNManager.isHosting check), and send (Time.time + TNManager.ping). On the clients, add TNManager.ping to it as well. Record the difference between the value and your own Time.time, and use this offset in the future.
