The glass is half empty or half full, depending on who you talk to.

The number of office key cards used in the Big Apple last week crossed the 50 percent threshold last week for the first time since the coronavirus struck more than three years ago, after weeks of it being stuck in the 40s, data collected by an office security firm shows.

The uptick — amid the soot-laden smoke shroud from Canadian wildfires that turned the skies orange and forced officials to recommend the public remain indoors — was a hopeful sign for city officials, who rely on office towers in Manhattan to provide billions in tax revenues every year.

“NYC just passed an important milestone: Last week for the first time since the pandemic in-person office occupancy passed 50% (and that despite the smoke from Canada),” tweeted the borough’s president, Mark Levine.

City and state officials and local business leaders have long argued that getting folks back to office is essential for the city’s economy, in part because of the tax revenues and in part because there are thousands of service jobs that are dependent on folks coming in.

The slow return to the office has also forced the MTA to rework its finances and seek a billion dollar tax hike from Albany to cover the lost revenue from commuters who stopped riding after they switched to work-from home.

Weekday subway ridership is hovering at about 70 percent of its pre-pandemic average.

The data is collected by Kastle Systems, which operates key card systems in office towers in many of the country’s most important business hubs.

It shows New York continues to trail Houston and the Chicago in returning to the office, but leads Philadelphia, Washington D.C., San Francisco and Los Angeles.

Nearly 62 percent of workers in Houston tapped or swiped into the office last week, the data showed; while just 42 percent of the badges in the City of Brotherly Love were used.