Once again, the three major television networks have agreed to refrain from making election-day forecasts of winners until after the polls are closed in every state, not counting Alaska and Hawaii. Let's hope they can keep their pledge this time.

The networks - ABC, CBS, and NBC - had made the commitment previously, although NBC broke the pledge in the New York Democratic presidential primary this year by announcing results of exit polls while voting places were still open. NBC officials say it won't happen again.This jumping the gun with forecasts of winners, based on interviewing people as they come out of voting places, has been one of the more irritating practices of television on election night - trying to predict the news instead of simply reporting it.

With the latest agreement in hand by TV executives, Congress is considering a bill to have all polling places across the land close at the same moment. A uniform closing law now before the Senate would close voting places in the Eastern time zone at 9 p.m., which would be 8 p.m. in the Midwest, and 7 p.m. in the Mountain West. Daylight saving time would be extended until after the election in the Pacific time zone, so that polls in California, Oregon, Washington, Nevada, and the Idaho panhandle would also close at 7 p.m.

Those hours do not seem unreasonable and they have the virtue of keeping any change as simple as possible. It would cut the voting time in Utah by one hour, perhaps making it a little more difficult for some who wait until the evening to cast ballots.

A similar measure was approved last November in the House. The Senate bill currently is in the Senate Rules Committee, where it has solid support.

Such a uniform poll-closing is worth a try. If the plan doesn't work, it can always be changed - just as has been done with daylight savings time.