AFTER YEARS OF on-again, off-again experiments with daylight time, Congress has produced a logical proposal for a slight change in the current national schedule for clock-switching every year. It is this: begin Daylight Saving Time on the first Sunday of March instead of the last Sunday of April. It would end as it does now, on the last Sunday in October. For all who prefer the extra hour of light in the evenings--not merely for pleasure but for safer passage home after work, more opportunities for physical exercise and less bright sunshine in the pre-6 a.m. hours of spring mornings--this modest extension of the DST period has much appeal.

The earlier date for starting daylight time is not arbitrary. Congressman Richard Ottinger of New York, chief sponsor of the bill and chairman of the subcommittee that moved this measure to approval by the House Energy and Commerce Committee last week, notes that the proposal would make the period of daylight time symmetrical around the summer solstice, the day the sun shines longest each year. Other supporters, including the Reagan administration, argue that this change could help conserve energy and reduce crime--and they cite various studies to this effect.

Even if these claimed advantages are not all that sizable, neither are they outweighed by the traditional objections to any summertime clock changes. For example, Congressman Tom Daschle of South Dakota writes on today's "Free for All" page that farmers have difficulty tending to their animals when the morning daylight begins at a different time. But even if animals cannot adjust their biological clocks easily, farm chores can be carried out in earlier, darker hours, as they are during half the year already.

The House approved this proposal in the last Congress, but the Senate Commerce Committee never got to it. This year, both houses have time to enact the bill and settle this issue in a reasonable and welcome fashion.