Change system time programmaticaly using datetimepeaker

Question

I am trying to change system date and time using the following C# code. But the result is no change is occuring in systemdate(no error is thrown either). I tried by uncommenting the commented portion of the code too. But no effect. :( Afterward I tried to change time from command prompt.(not using c#) Then it showed "A required privilage is not held by the client." I know this message may not have any connection with the code, but I am adding it to make my situation clearer.

   [StructLayout(LayoutKind.Sequential)]
      public struct Systemtime
     {
        public ushort Year;
        public ushort Month;
        public ushort DayOfWeek;
        public ushort Day;
        public ushort Hour;
        public ushort Minute;
        public ushort Second;
        public ushort Millisecond;
     }
    /*
            [DllImport("kernel32.dll", EntryPoint = "GetSystemTime", SetLastError = true)]
            [return: MarshalAsAttribute(UnmanagedType.Bool)]
            public static extern bool Win32GetSystemTime([InAttribute]ref Systemtime sysTime);
     */
    [DllImport("kernel32.dll", EntryPoint = "SetSystemTime", SetLastError = true)]
    [return: MarshalAsAttribute(UnmanagedType.Bool)]
    public static extern bool Win32SetSystemTime([InAttribute]ref Systemtime sysTime);

    private void DateTimeSelectedButton_Click(object sender, EventArgs e)
    {
        //var neededtime = MonthChangePhenomenonDateTimePicker.Value - TimeSpan.FromHours(5)-TimeSpan.FromMinutes(30);
        // Set system date and time

        Systemtime updatedTime = new Systemtime();
        updatedTime.Year = (ushort)MonthChangePhenomenonDateTimePicker.Value.Year;
        updatedTime.Month = (ushort)MonthChangePhenomenonDateTimePicker.Value.Month;
        updatedTime.Day = (ushort)MonthChangePhenomenonDateTimePicker.Value.Day;

        // UTC time; it will be modified according to the regional settings of the target computer so the actual hour might differ
        updatedTime.Hour = (ushort)MonthChangePhenomenonDateTimePicker.Value.Hour;
        updatedTime.Minute = (ushort)MonthChangePhenomenonDateTimePicker.Value.Minute;
        updatedTime.Second = (ushort)MonthChangePhenomenonDateTimePicker.Value.Second;
        // Call the unmanaged function that sets the new date and time instantly
        Win32SetSystemTime(ref updatedTime);

        MessageBox.Show(@"You Have Current System Time: " + updatedTime);
    }

Please help me to know what is going wrong. Thanks in advance. :)

Answer 1

Hereafter is a C# Console Application to raise the SE_SYSTEMTIME_NAME based on the post "C# – How to enable SeDebugPrivilege?" of Tri Nguyen's Blog and tested on my Windows 7 64bits Laptop. Please don't forget to post a comment on this blog.

using System;
using System.Runtime.InteropServices;

namespace ConsoleApplication1
{
    class Program
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr GetCurrentProcess();

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool CloseHandle(IntPtr hHandle);

        [StructLayout(LayoutKind.Sequential)]
        public struct LUID
        {
            public UInt32 LowPart;
            public Int32 HighPart;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct TOKEN_PRIVILEGES
        {
            public UInt32 PrivilegeCount;
            public LUID Luid;
            public UInt32 Attributes;
        }

        [DllImport("advapi32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool OpenProcessToken(IntPtr ProcessHandle,
            UInt32 DesiredAccess, out IntPtr TokenHandle);

        [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool LookupPrivilegeValue(string lpSystemName, string lpName,
            out LUID lpLuid);

        // Use this signature if you do not want the previous state
        [DllImport("advapi32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool AdjustTokenPrivileges(IntPtr TokenHandle,
           [MarshalAs(UnmanagedType.Bool)]bool DisableAllPrivileges,
           ref TOKEN_PRIVILEGES NewState,
           UInt32 Zero,
           IntPtr Null1,
           IntPtr Null2);

        private static uint TOKEN_QUERY = 0x0008;
        private static uint TOKEN_ADJUST_PRIVILEGES = 0x0020;

        public const UInt32 SE_PRIVILEGE_ENABLED = 0x00000002;

        public const string SE_SYSTEMTIME_NAME = "SeSystemtimePrivilege";

        static void Main(string[] args)
        {
            IntPtr hToken;
            string sSEPrivilegeName = SE_SYSTEMTIME_NAME;
            LUID luidSEPrivilegeNameValue;
            TOKEN_PRIVILEGES tkpPrivileges;

            if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, out hToken))
            {
                Console.WriteLine("OpenProcessToken() failed, error = {0}. {1} is not available", Marshal.GetLastWin32Error(), sSEPrivilegeName);
                return;
            }
            else
            {
                Console.WriteLine("OpenProcessToken() successfully");
            }

            if (!LookupPrivilegeValue(null, SE_SYSTEMTIME_NAME, out luidSEPrivilegeNameValue))
            {
                Console.WriteLine("LookupPrivilegeValue() failed, error = {0}. {1} is not available", Marshal.GetLastWin32Error(), sSEPrivilegeName);
                CloseHandle(hToken);
                return;
            }
            else
            {
                Console.WriteLine("LookupPrivilegeValue() successfully");
            }

            tkpPrivileges.PrivilegeCount = 1;
            tkpPrivileges.Luid = luidSEPrivilegeNameValue;
            tkpPrivileges.Attributes = SE_PRIVILEGE_ENABLED;

            if (!AdjustTokenPrivileges(hToken, false, ref tkpPrivileges, 0, IntPtr.Zero, IntPtr.Zero))
            {
                Console.WriteLine("LookupPrivilegeValue() failed, error = {0}. {1} is not available", Marshal.GetLastWin32Error(), sSEPrivilegeName);
            }
            else
            {
                Console.WriteLine("{0} is now available", sSEPrivilegeName);
            }
            CloseHandle(hToken);
            Console.ReadLine();
        }
    }
}

Answer 2

Before calling the 'SetSystemTime' function, you have to raise the SE_SYSTEMTIME_NAME privilege by using the 'AdjustTokenPrivileges' function. This function is located in the Advapi32.dll.