Saturday 25th December: 8.30 EastEnders Fourth of today's nine visits to Albert Square 9.00 Walking with Dinosaurs It's `Dad's Army' again 10.00 Who Needs It? Christmas television, that is

It's every TV scheduler's favourite time of the year. But, really, why do they bother?

Christmas: the season of goodwill and, with luck, excellent television. What new films? What comedy specials? What light entertainment extravaganzas? It's at about this time of the year that the British population divides neatly into two:

1. Those people who, having bought the Radio Times, go through its pages with a felt-tip pen and encircle all the programmes they intend to watch; and

2. Those who mock such anally retentive behaviour and then, when no one's looking, encircle the programmes they intend to watch with a differently coloured felt-tip pen.

(Of course there are a few people who don't watch much television over Christmas. They go on long freezing walks, and are eventually forced to read the bulky literary biographies cruel relatives have given them for Christmas. They are the sort of people who actually look forward to going back to work in January.)

It's vital, then, to be first to the Radio Times when it comes out. For years the magazine's publishers have marvelled at the extraordinary sales figures they enjoy for their Christmas/New Year double issue. This is because unscrupulous TV viewers go out and buy a second copy, encircle all their favourite programmes and then quietly throw away the first copy. Some households can get through half a dozen.

It's also an explanation for all those Christmas TV schedules most newspapers print in a blaze of excitement at the beginning of December. "Exclusive!" they all scream, which is fair enough as most of them print slightly different listings for each of the crucial days. This is because none of the TV companies has finalised their schedules when the newspapers want to print them, so the newspapers have to fill the gaps with guesses. Oddly enough they forget to mention this to their inevitably disappointed readers.

The real Christmas schedules are concocted by a few brave and tortured souls sitting in small offices in the bowels of their respective television company headquarters. The programmes have been made, the new films have been bought, and the BBC's tape of The Great Escape has been dusted off for its first showing since Easter. Now it's just a matter of putting all these delights in the right order.

Unfortunately this is not as easy a task it may seem. Your audience's high expectations have been built up by years of Morecambe And Wise, which has ensured that, for the next 50 years at least, no Christmas TV will ever be quite as good as it used to be. The fact that in 1971 the only alternative programming was an On The Buses Christmas Special is conveniently forgotten. Those were the days in which terrible old westerns really were the highlight of Boxing Day's viewing. Morecambe And Wise were the only people who kept us sane.

For BBC1, then, there is the unendurable weight of expectation, not to mention Noel Edmonds. An appalling accident of birth gave Britain's foremost light entertainment beardie a Christian name that carries unmistakeable echoes of Christ's own birthday (a coincidence that seems to have struck him from an early age). The BBC1 scheduler has therefore been lumbered for years past with Noel's Christmas Presents, an emetic seasonal Jim'll Fix It that sets the tone for the whole day. These days there's also the double, triple or quadruple helping of EastEnders to wade through, an endurance test so stiff that even the soap's most zealous followers are likely to be comatose by the time Beppe finally decks Phil, or Pauline Fowler is stung to death by killer bees.

One trend that has thankfully passed is the feature-length episode of your favourite sitcom or comedy drama. Remember Birds Of A Feather going to East Germany, or Lovejoy going to America and meeting Cliff Barnes? Huge budgets (for the BBC) but much smaller jokes, stretched beyond imagining by ecologically minded scriptwriters. Again, a couple of glasses of red wine removed all resistance. Whole families could be heard snoring through these contrived japes, which was often the first thing they had agreed about for years. These days the trend is to produce three or four bumper episodes of the same sitcom: three years ago Only Fools And Horses, last year Men Behaving Badly, this year The Vicar Of Dibley. This at least gives a semblance of continuity, although you may end up wanting to murder Dawn French by Boxing Day.

ITV, by tradition, has completely ignored Christmas, as advertisers have no interest in it. The weeks leading up to Christmas, fine, because everyone still wants you to buy things, but the actual Christmas holiday? No money in it, so no programmes in it either. This year, however, the network has made an exception. So anxious is it to maintain its audience share, and so earn bumper bonuses for its top executives, that three episodes of Who Wants To Be A Millionaire? have been earmarked for Christmas Day. What chance that the questions will be that little bit easier, the chances of someone winning that million that little bit greater?

True tellyheads, though, will look beyond peaktime, for the real pleasures of Christmas television tend to lie in the margins of morning, afternoon and late night. If you look hard enough you can usually find: several Christmas sitcom specials from long ago, all hopelessly unfunny; carol concerts (always shown several days before Christmas to catch you out); dismal American documentaries about stunts, usually narrated by Lee Majors; at least seven news reviews of the year; an Audie Murphy season on BBC2; an inspired selection of Channel 4's dullest documentaries; Von Ryan's Express; The World's Strongest Man (no longer won by Geoff Capes); the Royal Institution Christmas lectures; Disney Time, hosted by someone much younger than you who is apparently very famous; a recent compilation of Bugs Bunny cartoons with feeble links voiced by someone other than Mel Blanc; Casablanca; and if you're really lucky, a classic episode of Mary Mungo and Midge. Does the mouse press the lift button? You betcha.

Amid all this hullabaloo there is only one certainty: that the two films you most want to tape will be on at the same time. Who'd be a scheduler at Christmas? Or, rather, who wouldn't?