TimeZoneInfo.CreateCustomTimeZone Method (String, TimeSpan, String, String)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Creates a custom time zone with a specified identifier, an offset from Coordinated Universal Time (UTC), a display name, and a standard time display name.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public static TimeZoneInfo CreateCustomTimeZone(
	string id,
	TimeSpan baseUtcOffset,
	string displayName,
	string standardDisplayName


Type: System.String

The time zone's identifier.

Type: System.TimeSpan

An object that represents the time difference between this time zone and Coordinated Universal Time (UTC).

Type: System.String

The display name of the new time zone.

Type: System.String

The name of the new time zone's standard time.

Return Value

Type: System.TimeZoneInfo

The new time zone.

Exception Condition

The id parameter is null.


The id parameter is an empty string ("").


The baseUtcOffset parameter does not represent a whole number of minutes.


The baseUtcOffset parameter is greater than 14 hours or less than -14 hours.

This overload of the CreateCustomTimeZone(String, TimeSpan, String, String) method is suitable for creating a time zone that has no adjustments (that is, a time zone that does not support daylight saving time). To define a time zone that includes adjustments for daylight saving time, use either the TimeZoneInfo.CreateCustomTimeZone or the TimeZoneInfo.CreateCustomTimeZone method.

The following table shows the relationship between the parameters that are provided to the TimeZoneInfo.CreateCustomTimeZone method and the properties of the TimeZoneInfo object that are returned by the method call.

CreateCustomTimeZone parameter

TimeZoneInfo property









Typically, the time zone's standard time name and its identifier are the same. However, the length of the time zone's identifier should not exceed 32 characters. The string passed to the displayName parameter follows a fairly standard format. The first portion of the display name is the time zone's base offset from Coordinated Universal Time, which is indicated by the acronym GMT (for Greenwich Mean Time), enclosed in parentheses. This is followed by a string that identifies the time zone itself, or one or more of the cities, regions, or countries in the time zone, or both. For example:

(GMT+02:00) Athens, Beirut, Istanbul, Minsk
(GMT-02:00) Mid-Atlantic
(GMT-07:00) Mountain Time (US & Canada)

The following example creates a custom time zone for the Mawson and Holme Bay regions of Antarctica. It then displays the result of converting the local time to the time in the new time zone.

string displayName = "(GMT+06:00) Antarctica/Mawson Time";
string standardName = "Mawson Time"; 
TimeSpan offset = new TimeSpan(06, 00, 00);
TimeZoneInfo mawson = TimeZoneInfo.CreateCustomTimeZone(standardName, offset, displayName, standardName);
Console.WriteLine("The current time is {0} {1}", 
                  TimeZoneInfo.ConvertTime(DateTime.Now, TimeZoneInfo.Local, mawson),

.NET Framework
Available since 3.5
Return to top