API/User-Terminal.md

@@ -122,3 +122,16 @@ POST to the API endpoint '/api/pager' to make the user terminal's LED flash brie
 ```sh
 curl -X POST http://<hostname>:<port>/api/pager
 ```
+
+# Time Synchronization
+
+The API endpoint '/api/timesync' provides basic information about the state of NTP clock synchronization on the user terminal. The returned JSON object provides the IP address of the NTP server being used (the base station in most cases) and an offset of the terminal's clock from the NTP server clock in seconds, as measured by the NTP protocol.
+```sh
+curl http://<hostname>:<port>/api/timesync
+```
+```json
+{
+  "server" : "10.10.255.254",
+  "offset" : 0.000525
+}
+```