Daylight saving time changes in Pennsylvania, United States

Pennsylvania uses the IANA time zone identifier America/New_York. The current local offset is UTC-4 / EDT.

Best Time to Call Pennsylvania

Business hours in Pennsylvania (9 AM-5 PM local time) fall at these local times elsewhere:

• Sao Paulo: 10:00 AM - 6:00 PM ( Convenient)
• Frankfurt: 3:00 PM - 11:00 PM ( Partial overlap)
• Johannesburg: 3:00 PM - 11:00 PM ( Partial overlap)
• Singapore: 9:00 PM - 5:00 AM (next day) ( Partial overlap)
• Hong Kong: 9:00 PM - 5:00 AM (next day) ( Partial overlap)
• Istanbul: 4:00 PM - 12:00 AM (next day) ( Partial overlap)
• Auckland: 2:00 AM (next day) - 10:00 AM (next day) ( Outside normal hours)

Times shown reflect current UTC offsets and may shift by up to an hour around daylight saving transitions.

Current Time in Cities of Pennsylvania, United States

About Time in Pennsylvania

The Observatory That Invented Standard Time

Long before railroads across the country agreed on four shared time zones, a single Pittsburgh observatory was already selling the idea of standardized time to anyone willing to pay for it. Samuel Pierpont Langley arrived at the Allegheny Observatory in 1867 to direct what was then the astronomy department of the Western University of Pennsylvania, today the University of Pittsburgh, and quickly recognized that the growing railroad network desperately needed a single, trustworthy source of accurate time. Using a small transit telescope to track stars crossing the meridian, Langley devised what became known as the Allegheny Time System starting in 1869, distributing precise time signals by telegraph first to local businesses and then, through the Pennsylvania Railroad, across thousands of miles of track.

The system grew rapidly and profitably. By 1870, Allegheny time reached roughly 2,500 miles of railway through 300 telegraph offices, and it eventually stretched across more than 4,700 miles of line serving railroads throughout the United States and Canada, earning the observatory more than 60,000 dollars over its years of operation, money Langley used to fund further astronomical research. Historians of timekeeping consider the Allegheny Observatory's service to be the first regular, systematic distribution of standard time anywhere in the country, effectively laying the groundwork for the four official time zones that railroads adopted nationwide on November 18, 1883, the same day Allegheny itself transmitted a signal marking the change.

The Joke That Became a Legend

Benjamin Franklin, Philadelphia's most famous resident, is routinely credited with inventing daylight saving time, but the truth behind that claim is considerably stranger than the myth. In 1784, while serving as the American envoy in Paris at age 78, Franklin was jolted awake at 6 a.m. by sunlight streaming through his window, a full six hours earlier than his usual habit of staying up late and sleeping until noon. Struck by how much money Parisians might save on candles if they simply matched their waking hours to the sun, he wrote a satirical letter to the Journal de Paris titled An Economical Project, published on April 26, 1784, calculating with mock seriousness that the city could save the modern equivalent of roughly 200 million dollars a year in candle wax.

Franklin's proposed solutions were not remotely practical, and were never meant to be. Among his tongue in cheek suggestions were taxing any window fitted with shutters that blocked sunlight, rationing candles per household, and firing cannons at sunrise to physically wake the city's late sleepers. He was parodying his own reputation for thrift and his notoriously late nights playing chess in Parisian salons, not proposing that anyone actually adjust their clocks, and the modern practice of daylight saving time would not be seriously proposed by anyone until English builder William Willett campaigned for it more than a century later, in the early 1900s, with Germany becoming the first country to formally adopt it during the First World War.

Three Competing Bills, One Unresolved Clock

Pennsylvania's state legislature has spent recent years pulling in three separate directions on the question of ending the twice yearly clock change, with no single approach yet winning out. In April 2021, the state House passed House Bill 335 by a close vote of 103 to 98, a measure sponsored by Representative Ryan Mackenzie that would commit Pennsylvania to permanent daylight saving time, but only once Congress amends federal law to allow it, since current law permits states to opt into standard time permanently but not daylight time. Mackenzie reintroduced a similar measure in 2023 as House Bill 272, arguing that ending the biannual switch would improve public safety and reduce traffic accidents linked to the disruption.

At the same time, two rival proposals have moved through Harrisburg pulling in different directions entirely. Representative Russ Diamond has repeatedly pushed his own bill that would instead lock Pennsylvania onto permanent standard time, a change state legislatures can make on their own without waiting for Congress, citing concern that permanent daylight time would leave schoolchildren waiting for buses in the dark through winter mornings. Separately, state Senator Lisa Boscola has proposed moving Pennsylvania out of the Eastern time zone altogether and onto Atlantic Standard time year round, a maneuver that would functionally deliver permanent daylight saving time without requiring any change in federal law at all. With three genuinely different bills advancing at various points and none securing final passage, Pennsylvania remains a state whose lawmakers agree the twice yearly clock change should end, but cannot yet agree on what should replace it.

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