# Wolfram Mathematica

## Compare Time Zones

Get the current numeric offset from GMT for Central Time.

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`TimeZoneOffset[Entity["TimeZone", "America/Chicago"]]`
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Get the offset relative to a different time zone on a specific date.

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```TimeZoneOffset[Entity["TimeZone", "America/Chicago"], Entity["TimeZone", "Europe/London"], DateObject[{2015, 3, 7}]]```
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Get a geographical representation of a time zone's region.

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`GeoGraphics[{Orange, Polygon[Entity["TimeZone", "Europe/London"]]}]`
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Compare the difference in offset for various parts of Indiana between two dates.

show complete Wolfram Language input
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```zones = {Entity["TimeZone", "America/Chicago"], Entity["TimeZone", "America/New_York"], Entity["TimeZone", "America/Indiana/Indianapolis"], Entity["TimeZone", "America/Indiana/Knox"], Entity["TimeZone", "America/Indiana/Marengo"], Entity["TimeZone", "America/Indiana/Petersburg"], Entity["TimeZone", "America/Indiana/Tell_City"], Entity["TimeZone", "America/Indiana/Vevay"], Entity["TimeZone", "America/Indiana/Vincennes"], Entity["TimeZone", "America/Indiana/Winamac"]}; colorFunction[-6.] = Yellow; colorFunction[-5.] = Orange; colorFunction[-4.] = Red; Legended[Grid[ Partition[ Map[With[{date = #}, Framed@GeoRegionValuePlot[ Rule[#, colorFunction[ TimeZoneOffset[#, "GMT", date]]] & /@ zones, PlotLabel -> DateString[#, {"MonthName", " ", "Day", " ", "Year"}], GeoRange -> Entity["AdministrativeDivision", {"Indiana", "UnitedStates"}], PlotStyle -> Opacity[.5]]] &, {DateObject[{2005, 2, 1}], DateObject[{2005, 5, 1}], DateObject[{2007, 2, 1}], DateObject[{2007, 5, 1}]} ], 2]], SwatchLegend[colorFunction /@ {-6., -5., -4.}, {-6., -5., -4.}, LegendLabel -> "GMT Offset"]]```
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