While General Motors has decided to cancel some or all of the usual summer break for many of its U.S. assembly plants to make up for production lost during the early months of the COVID-19 pandemic, GM Canada says its plans remain in flux.

Most GM plants in the United States will stay open the weeks of June 29 and July 6, a period when they normally would be closed, spokesman Jim Cain said.

“Thanks to excellent teamwork, the restart of vehicle production at GM’s manufacturing facilities continues to go safely and smoothly,” Cain said.

Plans in Canada, where the automaker assembles the Chevrolet Equinox in Ingersoll, stamps some of the vehicle’s parts in Oshawa, and operates a powertrain plant in St. Catharines, are still being determined.

“GM Canada is not planning a standard time frame for a manufacturing summer shut down period,” spokeswoman Jennifer Wright said. “We anticipate continuing to run portions of the St. Catharines plant to meet strengthening customer demand.”

Production at the plants resumed May 18.

“Thanks to excellent teamwork, the restart of vehicle production at GM Canada’s manufacturing facilities continues to go safely and smoothly,” Wright said.

The plan for GM’s CAMI plant in Ingersoll is “not determined at this time,” Wright said.

South of the border, a handful of Ford’s U.S. assembly plants will have a one-week summer shutdown, rather than the typical two-week stoppage, according to a Ford memo posted online by one UAW local. Chicago Assembly, Louisville Assembly and Kentucky Truck will be down only the week of June 29, while Flat Rock Assembly will be down for only the week of Aug. 3, according to the memo.

The rest of Ford’s assembly plants are scheduled for a two-week shutdown sometime between late June and mid-October.

A Ford spokeswoman did not immediately confirm the company’s shutdown plans.

Ford Canada didn’t respond to multiple requests for comment Monday or Tuesday.

Meanwhile, FCA did not provide any information about its summer production schedule in either country.

Monday was the contractual deadline for the Detroit 3 to notify the UAW of any changes to the plants’ schedule. Unifor wasn’t immediately available for comment in Canada.

Most auto plants in North America were closed from mid-March to May 18, when the automakers began to gradually restart production. The Detroit 3 and the UAW created a joint task force to help mitigate the spread of the virus at the plants. Workers must follow new health and safety protocols that include wearing face masks, temperature screenings, physical distancing and filling out health questionnaires.

Greg Layson of Automotive News Canada and Hannah Lutz and Michael Martinez of Automotive News contributed to this report.