Schedules

If there is a date stamp below the TV set, like this for example.....

.......then this means the set is following the TV listings of a specific day.
The set will always match up with the same day of the week rather than the actual date, so on a Monday the set will always go with a Monday schedule etc. but it will choose a schedule from the same calendar month.
If there is no date stamp, this means there is a generic schedule or - if BBC channels have a date stamp and ITV does not - then not all regional variations* for the location selected are included for that particular day.

*Thames and ATV opt-outs are almost always included, usually Granada, Yorkshire and Southern as well.

50th anniverssary schedules
The set is now mostly following what was being shown 50 years ago.

Christmas & New Year schedules
Christmas into new year follows a specific year depending on which day Christmas Day falls.....
If Christmas Day is on a Monday, all three channels follow the xmas 1978 schedules for the duration of the holiday period. On a Tuesday then it's xmas 1973, Wednesday is xmas 1974, Thursday is xmas 1975, Friday is xmas 1970, Saturday is xmas 1971 and Sunday is xmas 1977.
 

Programmes are represented either by a GIF animation of the opening titles, a screen grab of the titles, a holding slide or an embedded youtube video. In some cases it has been necessary to use a mocked up slide because no original image is available. Most programme slots on BBC1 are preceded by the clock and the BBC globe ident. A similar arrangement is used for BBC2 whilst on ITV there is a window for a 30 second GIF animated advertisement before the regional clock counts down the seconds to the start of the next programme which begins with the ident of the company who produced it.

Schedule information is also available on a month by month basis on teletext page 903.
The day's BBC1 listings are available on Ceefax page 171, BBC2 page 252 and ITV on Oracle page 101.
Teletext is not available on dates before 23rd September 1974.