It was 6:23 p.m. Sunday when President Carter rolled the last heavy dice of the 1980 campaign, a time that no media expert would have chosen. The only attraction on television at that hour was football but, like the Redskins-Vikings fiasco, they weren't big games or exciting either.

CBS broke into its football for a live broadcast of the president's remarks on the new conditions from Iran for release of the 52 American hostages. NBC recorded Carter and played him back 10 minutes later, also during football. Of the three networks only ABC had an evening news show Sunday night, which gave full coverage to Carter's statement, but probably had a small audience, because Americans aren't so interested in news over the weekend.

Still, tens of millions of Americans saw Carter in his last truly presidential moment of the campaign. Several millions more who have stayed up for late-night news programs on all three networks saw him, too. But it is assumed in the political business that most Americans catch up on the weekend news Monday so most people probably didn't tune in to the news from Iran and Washington until Monday morning.

And, because of the peculiar standards of the television news business, by Monday morning Carter's last roll of the dice -- barely 12 hours old by the clock -- was already stale.

On the "Today" show the hourly and half-hourly news bulletins did not include any footage of the president's Sunday evening remarks. "Good Morning America" on ABC showed them once a 7 a.m CBS's "Morning" program used a clip of Carter late in its show to illustrate a piece of media criticism. The bigger news Monday morning was the late word from Tehran that Ayatollah Ruhollah Khomeini had authorized the transfer of the hostages out of the hands of their militant captors.

Monday morning's television was a lesson in the meaning of the fashionable, if little-analyzed, term "media overkill." The purveyors of news obviously felt overwhelmed by the moment: the tight election campaign coming to a close, dramatic announcements from Iran that seemed to be the first genuinely good news in a year on the hostages, a vulnerable president struggling to preserve his job and also the appearance of dignity and honesty -- an overload.

The result was three network shows overloaded with reaction and commentary, but undernourishing in useful facts. None of the three made a serious effort to help a non-expert viewer cope with the news from Iran or Carter's reactions to it. They were all in too much of a hurry to explain the political implications or too eager to share the emotion of the hostages' families to explain in serious terms the new developments.

The viewer of any of the three programs got a jumbled sense of what was going on, and a jumbled impression about how or if or why these latest events were connected to the presidential election. There was a once-again-jowly Henry Kissinger suggesting that the United States would be regarded "with contempt" if Carter accepted the latest Iranian terms. There were hostage wives and mothers saying the new conditions seemed to be a good basis for a deal. There were White House officials sounding statemanlike but also vague and noncommittal -- Jack Watson on ABC and Jody Powell on NBC.

So Carter got only a modest ride from his last big moment, a fact whose significance remains to be seen. Indeed, the significance of most messages sent into American homes by television is often missed at first. History may conclude, for example, that Carter made an enormous goof in last week's debate when he said he had "had a discussion with my daughter Amy" about nuclear arms control. It looked like a small piece of saccharine demogoguery at the time, but perhaps by trivializing what was one of Carter's best issues and opening the president to all kinds of jokes and cartoons since, this was a truly grave mistake.

History may also conclude that Carter was inhibited from exploiting that last roll of the dice because he was so anxious to avoid the impression that he was making political hay out of the hostages. Carter had to be anxious about this precisely because he had made political hay out of the hostages intermittently all year.

Had he not used the hostage crisis as an excuse to avoid a direct confrontation with Sen. Edward M. Kennedy, had he not exploited it again in a desperate (and successful) attempt to win the Wisconsin primary with an early-morning, for-the-cameras optimistic statement that proved false, Carter might have been able to really exploit Sunday's opportunity.

Carter might have waited until prime time to go on television, and he might have made a more dramatic, inherently more political statement. As it was, the Carter camp sensed that grandstanding now would have backfired.

If, as some scholars of modern media politics believe, "Momentum" is the key to electoral success, then the messages sent into American livingrooms during the last day and a half of the campaign are good news for Ronald Reagan. Whatever else Carter conveyed in these final hours, it was not a sense of momentum.

All three network news shows last night concentrated on the Iranian news, putting politics in a secondary position. ABC and CBS made no attempt to predict the outcome, but NBC repeated a prediction made late Sunday night and on yesterday's "Today" show that Reagan will win the election.

If those final evening news programs had any impact on today's voting, it may have come not from the daily Iran news or the last-day reports on the candidates, but from special segments alll three networks did to mark the first anniversary today of the hostages' captivity.

CBS' was the longest and most vivid. Correspondent Charles Osgood reviewed the agonies of the past year, with accompanying film clips of the worst moments: blindfolded American diplomats in Tehran, a burnt-out American helicopter in the desert, Richard Queen's emotional arrival home and many more. Osgood recalled Carter's political maneuvering around the hostage crisis, and implicitly also recalled for 25 million or 30 million viewers the adminstration's failure to cope successfully with this national embarrassment.

Of course by last night the networks were already distracted by tonight's election return extravaganzas, which for all of them represent the most important "news event" of the quadrennium. Tonight the anchormen, pundits and correspondents will bring to a close in a thoroughly appropriate fashion the great media event that is an American presidential campaign.