pinvoke.net: Edit: kernel32.SetLocalTime

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@pinvoke=http://pinvoke.net/$$$.htm

Summary: Sets the current local time and date.

!!!!C# Signature:
 [DllImport("kernel32.dll")]
 static extern bool SetLocalTime([In] ref SYSTEMTIME lpLocalTime);
!!!!VB Signature:
 <DllImport("kernel32.dll")> _
 Shared Function SetLocalTime(ByRef time As SYSTEMTIME) As Boolean
 End Function
!!!!User-Defined Types:
None.

!!!!Notes:
Ian Moores added :
Note that on XP although in the background the time changes, the time displayed often does not change. I am yet to discover why and how to fix this

Paul Sawyer added:
SetLocalTime only succeeds if the application is running as an administrator.

!!!!Tips & Tricks:
	//I have added some methods to structure SYSTEMTIME. After that the convertion between System.DateTime and SYSTEM became much easier. :)
	//Sample Code in C#:

//Sample code for SetLocalTime and SYSTEMTIME structure
	//Author:	Yuan Xiaohui from www.farproc.com 
	//Time :	August 30th, 2005

using System;
	using System.Runtime.InteropServices;

public class MyClass1
	{
		/// <summary>
		/// SYSTEMTIME structure with some useful methods
		/// </summary>
		public struct SYSTEMTIME
		{
			public ushort wYear;
			public ushort wMonth;
			public ushort wDayOfWeek;
			public ushort wDay;
			public ushort wHour;
			public ushort wMinute;
			public ushort wSecond;
			public ushort wMilliseconds;

/// <summary>
			/// Convert form System.DateTime
			/// </summary>
			/// <param name="time"></param>
			public void FromDateTime(DateTime time)
			{
				wYear = (ushort)time.Year;
				wMonth = (ushort)time.Month;
				wDayOfWeek = (ushort)time.DayOfWeek;
				wDay = (ushort)time.Day;
				wHour = (ushort)time.Hour;
				wMinute = (ushort)time.Minute;
				wSecond = (ushort)time.Second;
				wMilliseconds = (ushort)time.Millisecond;
			}

/// <summary>
			/// Convert to System.DateTime
			/// </summary>
			/// <returns></returns>
			public DateTime ToDateTime()
			{
				return new DateTime(wYear, wMonth, wDay, wHour, wMinute, wSecond, wMilliseconds);
			}
			/// <summary>
			/// STATIC: Convert to System.DateTime
			/// </summary>
			/// <param name="time"></param>
			/// <returns></returns>
			public static DateTime ToDateTime(SYSTEMTIME time)
			{
				return time.ToDateTime();
			}
		}

//SetLocalTime C# Signature
		[DllImport("Kernel32.dll")]
		public static extern bool SetLocalTime( ref SYSTEMTIME Time );

//Example
		private void Add7Days

{
			//Get current time and add 7 days to it
			DateTime t = DateTime.Now.AddDays(7);
			//Convert to SYSTEMTIME
			SYSTEMTIME st = new SYSTEMTIME();
			st.FromDateTime(t);
			//Call Win32 API to set time
			SetLocalTime(ref st);
		}
	}
!!!!Sample Code in VB:
 Imports System.Runtime.InteropServices

Public Class Class1
   <StructLayout(LayoutKind.Sequential)> _
   Private Structure SYSTEMTIME
     <MarshalAs(UnmanagedType.U2)> Public Year As Short
     <MarshalAs(UnmanagedType.U2)> Public Month As Short
     <MarshalAs(UnmanagedType.U2)> Public DayOfWeek As Short
     <MarshalAs(UnmanagedType.U2)> Public Day As Short
     <MarshalAs(UnmanagedType.U2)> Public Hour As Short
     <MarshalAs(UnmanagedType.U2)> Public Minute As Short
     <MarshalAs(UnmanagedType.U2)> Public Second As Short
     <MarshalAs(UnmanagedType.U2)> Public Milliseconds As Short
   End Structure

<DllImport("kernel32.dll")> _
   Private Shared Sub GetLocalTime(ByRef time As SYSTEMTIME)
   End Sub

<DllImport("kernel32.dll")> _
   Private Shared Function SetLocalTime(ByRef time As SYSTEMTIME) As Boolean
   End Function

Public Sub SetsLocalTimeHourToEight()
     Dim currentTime As SYSTEMTIME
     GetLocalTime(currentTime)

currentTime.Hour = 8

SetLocalTime(currentTime)
   End Sub
 End Class

!!!!Alternative Managed API:
Do you know one?  Please contribute it!

Documentation: SetLocalTime@msdn on MSDN