MONTREAL -- The curfew has been a fact of life for Quebecers for months, but as millions of people gaze out their windows at a spring sun that's yet to set, many experts are casting doubts on the measure's effectiveness in combatting the spread of COVID-19. “Because curfews are not solitary creatures, they are usually deployed alongside other public health measures,” said Jonathan Jarry of the McGill Office for Science and Society. “It's difficult to find out if they, on their own, really do work.” On Saturday, protesters gathered in downtown Montreal to call for an end to the city's 8 p.m. curfew. It was the latest in a series of demonstrations that have united Quebecers of all political stripes.