Export (0) Print
Expand All

TimeZoneInfo.AdjustmentRule.DateStart Property

Gets the date when the adjustment rule takes effect.

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

public DateTime DateStart { get; }

Property Value

Type: System.DateTime
A DateTime value that indicates when the adjustment rule takes effect.

The value of the DateStart property is a date value without a time component.

You can assign DateTime.MinValue.Date to the DateEnd property when you create a custom adjustment rule for use in a time zone-aware application that does not have to work with historic time zone information.

Important noteImportant

   Unless there is a compelling reason to do otherwise, you should define the adjustment rule's start date to occur within the time interval during which the time zone observes standard time. Unless there is a compelling reason to do so, you should not define the adjustment rule's start date to occur within the time interval during which the time zone observes daylight saving time. For example, if a time zone's transition from daylight saving time occurs on the third Sunday of March and its transition to daylight saving time occurs on the first Sunday of October, the effective start date of the adjustment rule should not be January 1 of a particular year, since that date occurs within the period of daylight saving time.

By default, the registry in Windows XP defines a single adjustment rule whose start date is Monday, January 01, 0001 (the value of DateTime.MinValue.Date), for each time zone. For time zones in the United States, the registry in Windows Vista defines two adjustment rules:

  • Monday, January 01, 0001, to Sunday, December 31, 2006.

  • Monday, January 01, 2007, to Friday, December 31, 9999.

This means that, although time zone adjustment rules stored in the registry are useful for performing current time zone-related operations, they cannot be reliably used for retrieving historical time zone information. For information about defining a custom time zone with multiple adjustment rules that can be used in a historical time zone-aware application, see How to: Create Time Zones with Adjustment Rules.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Show:
© 2014 Microsoft