Far enough into the wee hours for the Center City revelers to retire, it’s just the moon and a cup of hot coffee keeping Joe Brasky company on his drive from South Philly to City Hall. That’s the way Brasky likes it, the quiet and the coffee. After all, there’s business to be done, and time is of the essence.

Just as he’s done twice a year for the last decade, he takes the City Hall elevator 17 floors up — “Clock level, they call it." In no ceremonious fashion, he then flicks the buttons to cut the power and stop time.

Tasked with adjusting the four massive clocks atop the city as a building services manager at City Hall, Brasky is the man of the hour during daylight saving time, springing Philly forward and falling back with the seasons.

Starting with the north-facing clock and moving west, south, and finally east, Brasky cranks the dials on four small timepieces inside the tower, calibrating each 225-pound minute hand outside in turn.

“Little clocks control these giant clocks. It’s kind of cool,” he said. “Each individual clock has to be set, and it takes about five minutes to do each one. ... I set them each about two, three minutes ahead and use my phone to make sure they’re accurate.”

Since electricity replaced the 120-year-old clocks’ unreliable pneumatic gas pressure-powered system in 1947, the process is much more accurate and nowhere near as difficult as it once was, Brasky said. But it’s not without its flaws.

“Basically there’s electricity running through the clocks. So when there’s a power outage, the power goes out on the clocks, too,” he said.

When City Hall lost power last summer, Brasky found himself atop the tower again, synchronizing the city’s time.

And when things get really out of hand, Brasky and his team call on “Bob the clock guy,” also known as Bob Desrochers, a clockmaker based in Lititz, Lancaster County. In addition to emergency fixes, Desrochers visits the tower at least twice a year to care for the 26-foot-diameter clocks with faces larger than those on London’s Big Ben, oiling the gears and keeping the machinery ticking.

But setting the time on the city’s iconic clocks is only a small part of Brasky’s job. He helps manage security and maintenance at City Hall, the largest municipal building in the United States.

“Heat calls, air-conditioning calls, HVAC, you name it," he said. “They keep us busy all year.”

Oh, and one more thing, Brasky said: “We don’t have a bell.”

He can’t help if any others are ringing out of sync.

“We just make sure the clocks are right," he said. "People are looking up at this all day. It’s cool to know you’re making a difference.”