Silly clock question - ES15

When we set up our ES15 DVD recorder, we were psyched when it somehow acquired the time from the cable. How does it do that? And why does it take like 3 minutes?

We plug everything into a powerstrip which we normally turn off, just to save some electricity, and so that there isn’t a mess of live cords that could potentially catch fire or something while we’re away or asleep. At least a few times, when we turned on the powerstrip, it flashed 12:00 for only a few minutes and then showed the time - it got it from the cable. We like that. But recently it doesn’t seem to do it - it flashes 12:00 for hours, which drives us nuts. Our VCR just shows dashes - no flashing. Why can’t the ES15 be like that? The clock will acquire the time if I go into settings and tell it to acquire the time, but I don’t want to have to do that all the time. I want it to go get the time itself. So my question is, when I turn on the power strip, why is it sometimes able to get the time automatically without me telling it to in settings, but not other times?

Cathy

Time comes the atomic clock received on a PBS station (updates every few mins), tune to a PBS stantion and the time should update without your input.
Clock backup has no battery so will lose time if unpluged from AC power in a fairly short time (few hours).