TimeZone Class (System)

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Microsoft Visual Studio 2008/.NET Framework 3.5

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.NET Framework Class Library

TimeZone Class

Updated: November 2007

Represents a time zone.

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

Syntax

Visual Basic (Declaration)

<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public MustInherit Class TimeZone

Visual Basic (Usage)

Dim instance As TimeZone

[SerializableAttribute]
[ComVisibleAttribute(true)]
public abstract class TimeZone

Visual C++

[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class TimeZone abstract

/** @attribute SerializableAttribute */ 
/** @attribute ComVisibleAttribute(true) */
public abstract class TimeZone

JScript

public abstract class TimeZone

Remarks

A time zone is a geographical region in which the same standard time is used.

Important Note:
Whenever possible, use the TimeZoneInfo class instead of the TimeZone class.

You can use the TimeZone class to retrieve information about the current time zone, and to convert times from local time to Coordinated Universal Time (UTC) or vice versa. However, you cannot use the TimeZone class to represent time zones other than the local zone or to handle date and time conversions from one time zone to another. For this purpose, use the TimeZoneInfo class. You can use this class to retrieve information on any time zone defined on the local system, to create custom time zones, and to convert times from one time zone to another.

The TimeZone class supports only a single daylight saving time adjustment rule for the local time zone. As a result, the TimeZone class can accurately report daylight saving time information or convert between UTC and local time only for the period in which the latest adjustment rule is in effect. In contrast, the TimeZoneInfo class supports multiple adjustment rules, which makes it possible to work with historic time zone data.

Notes to Inheritors:

In addition to providing implementations for its abstract members (those marked MustOverride in Visual Basic), it is important that classes derived from TimeZone override the default behavior of the ToLocalTime method. This is because the default behavior of ToLocalTime in the .NET Framework version 2.0 does not depend on a call to GetUtcOffset, as it did in the .NET Framework versions 1.0 and 1.1. For details, see the ToLocalTime method.

Examples

The following example references and displays selected TimeZone class elements.

Visual Basic

' Example of selected TimeZone class elements.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic

Module TimeZoneDemo

    Sub Main( )

        Const dataFmt As String = "{0,-30}{1}"
        Const timeFmt As String = "{0,-30}{1:yyyy-MM-dd HH:mm}"

        Console.WriteLine( "This example of selected " & _
            "TimeZone class elements generates the following " & _
            vbCrLf & "output, which varies depending on the " & _
            "time zone in which it is run." & vbCrLf )

        ' Get the local time zone and the current local time and year.
        Dim localZone As TimeZone = TimeZone.CurrentTimeZone
        Dim currentDate As DateTime = DateTime.Now
        Dim currentYear As Integer = currentDate.Year

        ' Display the names for standard time and daylight saving 
        ' time for the local time zone.
        Console.WriteLine( dataFmt, "Standard time name:", _
            localZone.StandardName )
        Console.WriteLine( dataFmt, "Daylight saving time name:", _
            localZone.DaylightName )

        ' Display the current date and time and show if they occur 
        ' in daylight saving time.
        Console.WriteLine( vbCrLf & timeFmt, _
            "Current date and time:", currentDate )
        Console.WriteLine( dataFmt, "Daylight saving time?", _
            localZone.IsDaylightSavingTime( currentDate ) )

        ' Get the current Coordinated Universal Time (UTC) and UTC 
        ' offset.
        Dim currentUTC As DateTime = _
            localZone.ToUniversalTime( currentDate )
        Dim currentOffset As TimeSpan = _
            localZone.GetUtcOffset( currentDate )

        Console.WriteLine( timeFmt, "Coordinated Universal Time:", _
            currentUTC )
        Console.WriteLine( dataFmt, "UTC offset:", currentOffset )

        ' Get the DaylightTime object for the current year.
        Dim daylight As DaylightTime = _
            localZone.GetDaylightChanges( currentYear )

        ' Display the daylight saving time range for the current year.
        Console.WriteLine( vbCrLf & _
            "Daylight saving time for year {0}:", currentYear )
        Console.WriteLine( "{0:yyyy-MM-dd HH:mm} to " & _
            "{1:yyyy-MM-dd HH:mm}, delta: {2}", _
            daylight.Start, daylight.End, daylight.Delta )
    End Sub 
End Module 

'This example of selected TimeZone class elements generates the following
'output, which varies depending on the time zone in which it is run.
'
'Standard time name:           Pacific Standard Time
'Daylight saving time name:    Pacific Daylight Time
'
'Current date and time:        2006-01-06 16:47
'Daylight saving time?         False
'Coordinated Universal Time:   2006-01-07 00:47
'UTC offset:                   -08:00:00
'
'Daylight saving time for year 2006:
'2006-04-02 02:00 to 2006-10-29 02:00, delta: 01:00:00

// Example of selected TimeZone class elements.
using System;
using System.Globalization;

class TimeZoneDemo
{
    static void Main( )
    {
        const string dataFmt = "{0,-30}{1}";
        const string timeFmt = "{0,-30}{1:yyyy-MM-dd HH:mm}";

        Console.WriteLine(
            "This example of selected TimeZone class " +
            "elements generates the following \n" +
            "output, which varies depending on the " +
            "time zone in which it is run.\n" );

        // Get the local time zone and the current local time and year.
        TimeZone localZone = TimeZone.CurrentTimeZone;
        DateTime currentDate = DateTime.Now;
        int      currentYear = currentDate.Year;

        // Display the names for standard time and daylight saving 
        // time for the local time zone.
        Console.WriteLine( dataFmt, "Standard time name:", 
            localZone.StandardName );
        Console.WriteLine( dataFmt, "Daylight saving time name:", 
            localZone.DaylightName );

        // Display the current date and time and show if they occur 
        // in daylight saving time.
        Console.WriteLine( "\n" + timeFmt, "Current date and time:",
            currentDate );
        Console.WriteLine( dataFmt, "Daylight saving time?", 
            localZone.IsDaylightSavingTime( currentDate ) );

        // Get the current Coordinated Universal Time (UTC) and UTC 
        // offset.
        DateTime currentUTC = 
            localZone.ToUniversalTime( currentDate );
        TimeSpan currentOffset = 
            localZone.GetUtcOffset( currentDate );

        Console.WriteLine( timeFmt, "Coordinated Universal Time:", 
            currentUTC );
        Console.WriteLine( dataFmt, "UTC offset:", currentOffset );

        // Get the DaylightTime object for the current year.
        DaylightTime daylight = 
            localZone.GetDaylightChanges( currentYear );

        // Display the daylight saving time range for the current year.
        Console.WriteLine( 
            "\nDaylight saving time for year {0}:", currentYear );
        Console.WriteLine( "{0:yyyy-MM-dd HH:mm} to " +
            "{1:yyyy-MM-dd HH:mm}, delta: {2}", 
            daylight.Start, daylight.End, daylight.Delta );
    } 
} 

/*
This example of selected TimeZone class elements generates the following
output, which varies depending on the time zone in which it is run.

Standard time name:           Pacific Standard Time
Daylight saving time name:    Pacific Daylight Time

Current date and time:        2006-01-06 16:47
Daylight saving time?         False
Coordinated Universal Time:   2006-01-07 00:47
UTC offset:                   -08:00:00

Daylight saving time for year 2006:
2006-04-02 02:00 to 2006-10-29 02:00, delta: 01:00:00
*/

Visual C++

// Example of selected TimeZone class elements.
using namespace System;
using namespace System::Globalization;
int main()
{
   String^ dataFmt = "{0,-30}{1}";
   String^ timeFmt = "{0,-30}{1:yyyy-MM-dd HH:mm}";
   Console::WriteLine( "This example of selected TimeZone class "
   "elements generates the following \n"
   "output, which varies depending on the "
   "time zone in which it is run.\n" );

   // Get the local time zone and the current local time and year.
   TimeZone^ localZone = TimeZone::CurrentTimeZone;
   DateTime currentDate = DateTime::Now;
   int currentYear = currentDate.Year;

   // Display the names for standard time and daylight saving 
   // time for the local time zone.
   Console::WriteLine( dataFmt, "Standard time name:", localZone->StandardName );
   Console::WriteLine( dataFmt, "Daylight saving time name:", localZone->DaylightName );

   // Display the current date and time and show if they occur 
   // in daylight saving time.
   Console::WriteLine( String::Concat( "\n", timeFmt ), "Current date and time:", currentDate );
   Console::WriteLine( dataFmt, "Daylight saving time?", localZone->IsDaylightSavingTime( currentDate ) );

   // Get the current Coordinated Universal Time (UTC) and UTC 
   // offset.
   DateTime currentUTC = localZone->ToUniversalTime( currentDate );
   TimeSpan currentOffset = localZone->GetUtcOffset( currentDate );
   Console::WriteLine( timeFmt, "Coordinated Universal Time:", currentUTC );
   Console::WriteLine( dataFmt, "UTC offset:", currentOffset );

   // Get the DaylightTime object for the current year.
   DaylightTime^ daylight = localZone->GetDaylightChanges( currentYear );

   // Display the daylight saving time range for the current year.
   Console::WriteLine( "\nDaylight saving time for year {0}:", currentYear );
   Console::WriteLine( "{0:yyyy-MM-dd HH:mm} to "
   "{1:yyyy-MM-dd HH:mm}, delta: {2}", daylight->Start, daylight->End, daylight->Delta );
}

/*
This example of selected TimeZone class elements generates the following
output, which varies depending on the time zone in which it is run.

Standard time name:           Pacific Standard Time
Daylight saving time name:    Pacific Daylight Time

Current date and time:        2006-01-06 16:47
Daylight saving time?         False
Coordinated Universal Time:   2006-01-07 00:47
UTC offset:                   -08:00:00

Daylight saving time for year 2006:
2006-04-02 02:00 to 2006-10-29 02:00, delta: 01:00:00
*/

// Example of selected TimeZone class elements.
import System.*;
import System.Globalization.*;

class TimeZoneDemo
{
    public static void main(String[] args)
    {
        final String dataFmt = "{0,-30}{1}";
        final String timeFmt = "{0,-30}{1:yyyy-MM-dd HH:mm}";

        Console.WriteLine(("This example of selected TimeZone class " 
            + "elements generates the following \n" 
            + "output, which varies depending on the " 
            + "time zone in which it is run.\n"));

        // Get the local time zone and the current local time and year.
        TimeZone localZone = TimeZone.get_CurrentTimeZone();
        DateTime currentDate = DateTime.get_Now();
        int currentYear = currentDate.get_Year();

        // Display the names for standard time and daylight saving 
        // time for the local time zone.
        Console.WriteLine(dataFmt, "Standard time name:",
            localZone.get_StandardName());
        Console.WriteLine(dataFmt, "Daylight saving time name:",
            localZone.get_DaylightName());

        // Display the current date and time and show if they occur 
        // in daylight saving time.
        Console.WriteLine("\n" + timeFmt, "Current date and time:", 
            currentDate);
        Console.WriteLine(dataFmt, "Daylight saving time?",
            String.valueOf(localZone.IsDaylightSavingTime(currentDate)));

        // Get the current Coordinated Universal Time (UTC) and UTC 
        // offset.
        DateTime currentUTC = localZone.ToUniversalTime(currentDate);
        TimeSpan currentOffset = localZone.GetUtcOffset(currentDate);

        Console.WriteLine(timeFmt,"Coordinated Universal Time:", currentUTC);
        Console.WriteLine(dataFmt, "UTC offset:", currentOffset);

        // Get the DaylightTime object for the current year.
        DaylightTime daylight = localZone.GetDaylightChanges(currentYear);

        // Display the daylight saving time range for the current year.
        Console.WriteLine("\nDaylight saving time for year {0}:", 
            String.valueOf(currentYear));
        Console.WriteLine("{0:yyyy-MM-dd HH:mm} to " + 
            "{1:yyyy-MM-dd HH:mm},delta: {2}",
            daylight.get_Start(), daylight.get_End(),
            daylight.get_Delta());
    } //main
} //TimeZoneDemo

/*
This example of selected TimeZone class elements generates the following
output, which varies depending on the time zone in which it is run.

Standard time name:           Pacific Standard Time
Daylight saving time name:    Pacific Daylight Time

Current date and time:        2006-01-06 16:47
Daylight saving time?         False
Coordinated Universal Time:   2006-01-07 00:47
UTC offset:                   -08:00:00

Daylight saving time for year 2006:
2006-04-02 02:00 to 2006-10-29 02:00, delta: 01:00:00
*/

Inheritance Hierarchy

System..::.Object
System..::.TimeZone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information