Should advertisers pay for viewers whose their commercials as much as a week after they air? The answer may not come for a year or more.

In remarks to investors at a conference Monday evening, CBS CEO Leslie Moonves suggested the debate between TV networks and advertisers over the push to make "C7" -- or ratings measuring how many TV viewers see ads as much a seven days after they originally air -- the standard for discussions of TV-ad pricing could be tabled until 2014.

"I don't know if it happens this quickly, but it will happen within a year. It'll happen within a year," Mr. Moonves said.

"The measurement is already there. They give us C7 numbers now," he added. "Now it's a question of the advertising community and the networks and the programmers to come together and accept this," he said, acknowledging that some advertisers may require a reduction in price for being asked to pay for viewers after three days -- the current standard -- or ask for new commercials to be placed alongside a particular TV program.

His comments come just a few weeks before the TV-industry "upfronts" --- that time of year when the big broadcast and cable outlets try to sell the bulk of their ad inventory for the coming season -- get into full swing. The idea of putting "C7" into practice was believed to be one of the issues up for debate this year.

Mr. Moonves is the first -- and certainly the most prominent -- TV-industry executive to put forth the notion that Big TV's quest to make "C7" the standard may not happen with a snap of the fingers. His remarks run somewhat counter to those of Walt Disney Co.'s Bob Iger and NBC Universal's Ted Harbert, both of whom have said in recent months that the rise of time-delayed viewing of TV programs necessitates a move to count seven days' worth of views.

Don't misunderstand: CBS wants "C7" as much as anyone else, and would likely embrace it if it became a reality in 2013. As Mr. Moonves remarked Monday, "Some of our hit programs literally are only watched 60% now live. So the other 40% obviously is coming from DVR usage and, to a certain extent, online. What happens now, if you watch in the first three days on the DVR, we get paid in full. If it got -- gets watched later than that, that doesn't happen."

Ad buyers, however, are not so eager. In a December interview with Ad Age, one of the most influential media-agency executives said TV networks would be well advised to find a way to count viewers who watch TV, tablets, computer screens and other devices, so as to give marketers a better picture of total viewership of a program. Working to implement "C7," said Rino Scanzoni, chief investment officer of WPP's Group M, would not work as well as coming up with something more relevant to the ways in which TV viewership is changing.

"In the world we are going to now, where this media is becoming more fragmented and audiences are becoming more complicated to measure, I don't necessarily believe there's going to be one metric," Mr. Scanzoni said in the interview. "There could be different metrics for different clients based upon their specific needs and objectives." On Tuesday, Walt Disney's ABC, ESPN and ABC Family said they would partner with Nielsen to offer advertisers guarantees for viewers who watch programs on TV as well as online.

As for the idea of "C7," Mr. Scanzoni said in December, "I do not see a situation where there's going to be a broad move from C3 to C7" by a majority of TV-ad clients.