Daylight saving time changes in Wyoming, United States

Wyoming uses the IANA time zone identifier America/Denver. The current local offset is UTC-6 / MDT.

Best Time to Call Wyoming

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

• Sao Paulo: 12:00 PM - 8:00 PM ( Partial overlap)
• Frankfurt: 5:00 PM - 1:00 AM (next day) ( Partial overlap)
• Johannesburg: 5:00 PM - 1:00 AM (next day) ( Partial overlap)
• Singapore: 11:00 PM - 7:00 AM (next day) ( Outside normal hours)
• Hong Kong: 11:00 PM - 7:00 AM (next day) ( Outside normal hours)
• Istanbul: 6:00 PM - 2:00 AM (next day) ( Partial overlap)
• Auckland: 4:00 AM (next day) - 12:00 PM (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 Wyoming, United States

About Time in Wyoming

Yellowstone's Clock Made of Steam

Old Faithful, the most famous geyser in Yellowstone National Park, has earned its name by being one of the most reliably predictable natural phenomena on Earth, and park rangers have reduced that reliability to an actual formula. The rule is simple: if an eruption lasts less than about two and a half to three minutes, the next eruption will follow in roughly 60 to 68 minutes, but if the eruption runs longer than that threshold, the wait stretches to around 90 to 94 minutes. Rangers time each eruption from the moment water begins splashing continuously out of the cone until only steam remains, then add the appropriate interval to predict, with roughly 90 percent confidence within about a ten minute window, exactly when the geyser will perform again.

That underlying rhythm is not perfectly fixed, and it has visibly shifted over the decades in response to regional earthquakes. Before a major 1959 earthquake centered at nearby Hebgen Lake, Old Faithful erupted on an average interval of about 65 minutes; that quake, along with another in 1975 and a 1983 earthquake near Borah Peak in Idaho, gradually lengthened the average interval, which today runs closer to 90 minutes. A further shift followed a local earthquake in 1998, after which the geyser began favoring longer duration eruptions followed by longer waits far more often than the short duration, short wait pattern it had displayed for decades before, evidence that the plumbing feeding this particular clock lies deep enough to be reshaped by the same seismic forces that periodically reshape the rest of Yellowstone.

Five Years to Pass a Trigger Law

Wyoming's push to end its twice yearly clock change took half a decade of persistent effort from a single state legislator before it finally succeeded. Representative Dan Laursen of Powell first introduced a bill to keep Wyoming on daylight saving time year round in 2016, and pushed a version of the idea in nearly every session that followed, watching earlier attempts fail outright and a 2019 version die in the state Senate on a tied 15 to 15 vote. In 2020, his bill, House Bill 44, finally passed, and Governor Mark Gordon signed it into law, but the measure was written as a trigger law rather than an immediate change: Wyoming would only actually switch to permanent daylight saving time once Congress amended federal law to allow it and at least four of Wyoming's neighboring states, drawn from a list that included Colorado, Idaho, Montana, Nebraska, North Dakota, South Dakota, and Utah, passed matching legislation of their own.

That federal trigger still had not been pulled years later. When the U.S. House passed the Sunshine Protection Act by a vote of 308 to 117, Wyoming's own Representative Harriet Hageman was one of the no votes, arguing in a public statement that the change would rob the state's farmers and ranchers of precious morning sunlight and leave students waiting for the school bus in darkness. Because Wyoming's own 2020 law is contingent on federal action that has not yet occurred, even a House vote in favor of permanent daylight time changed nothing for the state immediately, leaving Wyoming's clocks unchanged and its law still waiting on Washington.

A Tower Named First, and a Calendar Kept in June

Three months after Congress handed the president a brand new tool for protecting significant American landscapes, Theodore Roosevelt used it for the very first time in Wyoming. On September 24, 1906, Roosevelt proclaimed Devils Tower, the sheer, columnar rock formation rising more than 1,200 feet above the Belle Fourche River in the state's northeast corner, as the first national monument ever designated under the Antiquities Act, a law signed only that June. Roosevelt would go on to designate seventeen more national monuments during his presidency, but Devils Tower carries the historical distinction of being first, a status driven partly by lobbying from Wyoming's own congressional delegation and partly by Roosevelt's own conviction that a dramatic geological formation qualified just as much as an archaeological ruin for federal protection.

Long before Roosevelt's proclamation, and continuing to the present day, the formation has held deep religious significance for several Native American nations, who consider it a sacred site for prayer and ceremony. That significance still shapes how the monument is managed on an annual, calendar driven basis: each June, when several tribes hold ceremonies at the site tied to their own religious calendar, the National Park Service asks rock climbers to voluntarily avoid climbing the tower for the month, a compromise reached after tribes lobbied for a formal ban. The vast majority of climbers now observe the voluntary June closure out of respect for the ceremonies, even those with no religious stake in the tradition themselves, making the tower's climbing calendar, alongside the geological one carved by weathering over tens of millions of years, one more way that a very old rock still keeps time with the people who visit it.

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