Viewer question

How is it possible for a pre-recorded program to run 20 minutes over schedule? Does it represent a complete disregard for viewers that the change in program length is not advertised either in the weekly program guide, or during the program itself. Of course, I wouldn't have cared except that I had already set the recorder to capture the program AFTER it, and while I give a 10 minute margin on either side of programs I'm recording, I knew it was unlikely the station would be able to make up the overrun.
So, why do they do it? Is it because they think you won't notice and then realise, too late, that you've missed the start of that program you were planning to watch on another channel? And that being the case, might as well just watch whatever their next offering is?
Which then brings us to the question of G-Code* recording. I will need to do some research on this to see if it is linked to the actual program - or whether, it too, is time-based. (Slight pause while internet is consulted.) Well, that settles it - G-Code just tells your machine what time to start recording, and isn't linked to the television stations and their programs. Interesting point noted from a forum I just visited: "the G code is only provided by the tv magazines,cause the station isnt allowed to assist in copyright violation".
Ah well, look slike I might need to give half an hour lee-way either end - except for the news - that always seems to begin and end at the advertised times!
* G-Code novices: if you go to your television program in some countries, after a program description you may find a series of numbers. If your recording device is G-Code-enabled, you can input these numbers to set up your recorder, rather than having to manually program station, time, date, duration etc - eg in Sydney today - Days of Our Lives 221890.