After 11 hours of debate in Hartford, state legislators approved a bill on Saturday to make Connecticut the first state in the nation to mandate paid sick leave for hundreds of thousands of service workers.

At about 3 a.m., the House voted 76 to 65 on the bill, which had been approved by an 18-to-17 vote in the Senate on May 25. About a dozen fiscally conservative House Democrats voted with the Republicans against the measure, which, while watered down from earlier proposals, had been vigorously denounced by business interests.

Proponents hailed the vote as a landmark victory for workers’ rights and public health at a time that similar measures are pending or about to be introduced in Philadelphia and Seattle and are being pushed elsewhere. Only San Francisco and Washington, D.C., now require employers to give paid sick days to workers.

Gov. Dannel P. Malloy, a first-term Democrat who had named paid sick days as a campaign issue, said in a statement that the bill was measured and fair. But Republicans and business interests called it onerous and ill-timed at a period in which businesses are struggling and job growth is anemic.