Based on this [url=http://vignette3.wikia.nocookie.net/dcs-powerless/images/7/73/C6avgIaXEAcqjZh.jpg/revision/latest?cb=20170309113233]promotional image[/url] for the Cold Season episode of Powerless. Charm City is in the Mountain Time Zone. Based on Metropolis and Gotham being East Coast at 6 and Charm City being at 4.

That means Charm City is in one of these states:
Arizona
Colorado
Idaho (southern half, south of the Salmon River)
Kansas (only the counties of Sherman, Wallace, Greeley and Hamilton)
Montana
Nebraska (western third)
New Mexico
North Dakota (southwestern quadrant, southwest of the Missouri River)
Oregon (most of Malheur County)
South Dakota (western half)
Texas (the two westernmost counties, Hudspeth & El Paso)
Utah
Wyoming