ALEXANDRIA, Va.—Restaurant hours have yet to normalize since the COVID-19 pandemic, according to new research by Datassential. The average restaurant is now open for 6.4 fewer hours per week than it was in 2019, which is a decline of 7.5%.

Increased food costs, supply chain disruptions and lack of labor availability have impacted restaurants, says Datassential, and because restaurants are not open as long as they used to, consumers today have fewer eating options—which is an opportunity for convenience retailers with a strong foodservice program.

There are more than 763,000 restaurants in the U.S., and 59% of them are operating on less hours now than before than in 2019. Independent restaurants are operating 7.5 hours less per week, and casual dining sit-down restaurants are open eight less hours.

“Chains have things like robotics, automation and technology upgrades that can largely enable them to make do without as many people,” Datassential co-founder and CEO Jack Li told CNBC.

All states saw a decline in restaurant operating hours, except Alaska, and the states and localities that were hit particularly hard were Washington, D.C. (-12.5 hours per week), Vermont (-11.3), Maine (-9.8), New York (-9.5), Connecticut (-9.2) and Minnesota (-9.2).

Denny’s (-30.1 hours per week), Texas Roadhouse (-21.2), IHOP (-17.7), Subway (-16.0) and Einstein Brothers (-14.2) are among the chains that reduced their hours the most.

Subway told CNBC that hours have dropped because of staffing issues. “While many restaurants have increased their hours to 2019 levels, for some franchisees, the biggest challenge to extending their hours continues to be labor,” a Subway spokesperson said in a statement to CNBC.

Texas Roadhouse told CNBC that a number of its restaurants located near office buildings opened for lunch on weekdays prior to the pandemic. Since lockdowns, most of those locations cut their lunch hours to focus on dinner.

The report also showed that the New York metropolitan area’s restaurants have trimmed hours by more than nine, and in one ZIP code of Manhattan’s East Village, three-quarters of restaurants are running on reduced hours.

A Seattle restaurant owner says labor is the reason for its reduced hours. Seattle restaurants are operating on 7.7 less hours. The restaurant, Cafe Champagne, was open seven days a week pre-pandemic, and now it’s open 4.5.

“I feel like if we were open seven days a week, we’d be happy with the revenue,” owner Daisley Gordon told CNBC.

Gordon says the restaurant needs more cooks but is slowly adding more staff and believes they will be back to seven days a week come spring.

The labor market, the economy and consumer behavior will dictate whether restaurants increase their operating hours, according to Datassential’s Li.

“My guess is the reduction in the restaurant hours is going to be with us for at least a little while,” he said.

Convenience stores could be taking market share from quick-serve restaurants. Food sales at c-stores have increased to over 20%, and the industry’s share of food sales has increased from 18.42% to 21.39% since 2019.

C-stores have the advantage for foodservice options due to quicker prep time, more variety and short wait times. The average wait at a QSR is about seven minutes, but it’s only four minutes on average to get your food at a convenience store. According to NACS State of the Industry data, foodservice accounted for 22.5% of in-store sales in 2021—significantly higher than the 16.8% reported a decade ago.