Automatic Time Syncronization

Back in the days of analog television, there was a time sync signal sent out on the educational channels.

My digital TV has a setting to allow the clock to be automatically synchronized but it does not work.  The manual states that the signal should be on digital channels, but either the TV does not recognize it or it is not present.   This TV is not connected to a cable box. 

Is the time sync signal still sent out on your network?   Is there a way to test this?