“I THINK it’s detrimental to democracy to have low levels of voter participation.” We couldn’t agree more with that assessment from University of Maryland government and politics professor Michael Hanmer in advance of Tuesday’s primaries in Maryland for local, state and federal offices. We hope voters turn out in healthy numbers, but pollsters are predicting that turnout in Maryland, as in other states that have held primaries this year, will be low.

In a recent Post poll, more than half of registered voters in Maryland said they were not paying attention to the state’s three-way gubernatorial Democratic primary, underscoring worries that the state might join California, Texas and the District of Columbia in posting low voter turnout. There can be many reasons for voter disinterest, but the date of a primary and how consistently a state maintains its schedule certainly can make a difference. In both Maryland and the District, September has long been the traditional time for primaries, but officials in both places said they had to change to comply with a new federal law making it easier for overseas service members to vote. The law requires that absentee ballots be mailed 45 days in advance of federal elections in November; officials said a September date didn’t provide enough time.

That didn’t leave good options. Too many people are away in July and August. District officials held their primary in April, which required campaigning in bad weather, depressed voter turnout and created an interminable nine-month period of lame duckery. Maryland’s late-June date may bump into vacations, graduations and weddings that are traditional at this time of the year.

In September, children are back in school, summer travel has concluded and voters may be more ready to think about election season. Five states — Delaware, New York, Massachusetts, New Hampshire and Rhode Island — have managed to keep their primaries in September and still comply with federal law. “We were determined we were not going to change the primary . . . so our discussion was, what did we need to do so we could keep the primary where we already had it,” New Hampshire Secretary of State Bill Gardner told us. He cautioned that what works for New Hampshire may not be practical for other jurisdictions. Nonetheless, we urge Maryland and D.C. officials to examine how these states have succeeded in maintaining their traditional primary schedule.