Daylight saving time changes in Ohio, United States

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

Best Time to Call Ohio

Business hours in Ohio (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 Ohio, United States

About Time in Ohio

The Astronomer in Cincinnati Who Invented the Idea of Time Zones

Before Chicago's railroad executives ever voted to adopt standard time in 1883, the theoretical groundwork for the entire system had already been laid in Cincinnati by an astronomer turned meteorologist named Cleveland Abbe. Appointed director of the Cincinnati Observatory in 1868, Abbe quickly found that his real challenge was not watching the stars but coordinating weather data from stations scattered across the country, a task that was essentially impossible without a shared, standardized clock.

To solve that problem, Abbe divided the United States into four standard time zones and, in 1879, published a paper titled "Report on Standard Time" laying out the case for the system. His reputation for reliability, earned issuing some of the country's first regular weather forecasts from Cincinnati, gave him the nickname "Old Probabilities" among the Western Union clerks who distributed his predictions. That same reputation gave his time zone proposal real weight. In 1883, Abbe personally helped convince North American railroad companies to adopt his four zone system, the same General Time Convention plan that produced the Day of Two Noons in Chicago that November. A year later, in 1884, his ideas helped inform the international discussions at the Meridian Conference that extended standardized time worldwide.

Abbe went on to lead the newly created United States Weather Bureau, the direct ancestor of today's National Weather Service, but the idea that eventually reorganized every clock in America had its roots in a Cincinnati observatory's struggle to know what time it actually was at every one of its scattered weather stations, all at once.

The Weather Data That Later Sent the Wrights to Kitty Hawk

The forecasting network Abbe helped build in Ohio did not stay confined to Cincinnati. By the time Wilbur and Orville Wright, two bicycle mechanics working out of their shop in Dayton, began seriously planning powered flight around 1900, they turned to the same federal Weather Bureau that had grown out of Abbe's original Cincinnati work to help choose a testing site.

The Wrights specifically selected the remote beach at Kitty Hawk, North Carolina, based on Weather Bureau data showing it offered consistently strong, steady winds far from crowded population centers, exactly the conditions their calculations demanded. Before making that trip, the brothers spent months back in their Dayton shop building a homemade wind tunnel and painstakingly timing and measuring lift and drag on dozens of wing shapes, refining the same kind of careful, standardized measurement that Abbe himself had once demanded of his scattered weather observers. The same state that helped invent the idea of a synchronized national clock also helped supply the data, indirectly, that got two Ohio brothers off the ground for the first successful powered flight in history.

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