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TimeZoneInfo::TransitionTime Structure

Provides information about a specific time change, such as the change from daylight saving time to standard time or vice versa, in a particular time zone.

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

[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
public value class TransitionTime : IEquatable<TimeZoneInfo..::.TransitionTime>, 
	ISerializable, IDeserializationCallback


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: MayLeakOnAbort | MayLeakOnAbort. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

You can use the TimeZoneInfo::TransitionTime structure to indicate when a transition from standard time to daylight saving time, or from daylight saving time back to standard time, occurs. This structure supports both fixed-date rules and floating-date rules. Use fixed-date rules for time transitions that occur on a specific day of a specific month (such as 2:00 A.M. on November 3). Use floating-date rules for time transitions that occur on a specific day of a specific week of a specific month (such as 2:00 A.M. on the first Sunday of November).


An instance of the TimeZoneInfo::TransitionTime structure is immutable. Once an object has been created, its values cannot be modified.

A TimeZoneInfo::TransitionTime object can be created by calling the static (Shared in Visual Basic) CreateFixedDateRule and CreateFloatingDateRule methods to create a fixed or floating-date rule, respectively. The starting and ending TimeZoneInfo::TransitionTime objects are then supplied as parameters to the CreateAdjustmentRule method to create a new adjustment rule that includes this transition time information.

The DaylightTransitionStart and DaylightTransitionEnd properties of an TimeZoneInfo::AdjustmentRule object return a TimeZoneInfo::TransitionTime object.

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

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

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.

.NET Framework

Supported in: 3.5