How To Change System Date and Time Using C#?

public struct SYSTEMTIME
{
public short wYear;
       public short wMonth;
       public short wDayOfWeek;
       public short wDay;
       public short wHour;
       public short wMinute;
       public short wSecond;
       public short wMilliseconds;
}

[DllImport("kernel32.dll", SetLastError = true)]
public static extern void SetSystemTime(ref SYSTEMTIME st);

public void SetSystemDateTime(DateTime ServerDateTime)
{
       ServerDateTime = ServerDateTime.AddHours(-5).AddMinutes(-30);
       SYSTEMTIME st = new SYSTEMTIME();
       st.wYear = (short)ServerDateTime.Year; // must be short
st.wMonth = (short)ServerDateTime.Month;
       st.wDay = (short)ServerDateTime.Day;
       st.wHour = (short)ServerDateTime.Hour;
       st.wMinute = (short)ServerDateTime.Minute;
       st.wSecond = (short)ServerDateTime.Second;
       st.wMilliseconds = (short)ServerDateTime.Millisecond;
       SetSystemTime(ref st);
}