The dog I had as a youngster told the time by television theme tunes. For example, he knew that when the 'Z Cars' theme was played at the end of the programme it was time for walkies and he'd go into a frenzy. However the theme tune was also played at the start of the programme, so we'd have to rush to turn the sound down then to stop him deciding it was already time to go out. (If we didn't, one of us would have to miss 'Z Cars' because he wouldn't calm down until he got his walk).