SetSystemTime stes wrong time

Question

here is my codes for changing my system time :
(i want to use them in my vps - windows server 2008 - r2)

[StructLayout(LayoutKind.Sequential)]
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 bool SetSystemTime(ref SYSTEMTIME theDateTime);

private void button1_Click(object sender, EventArgs e)
{
    DateTime now = DateTime.Now;

    SYSTEMTIME st = new SYSTEMTIME();
    st.wYear = short.Parse(now.Year.ToString()); // must be short
    st.wMonth = short.Parse(now.Month.ToString());
    st.wDay = short.Parse(now.Day.ToString());
    st.wDayOfWeek = short.Parse(((int)now.DayOfWeek).ToString());
    st.wHour = 5;
    st.wMinute = 20;
    st.wSecond = 30;
    st.wMilliseconds = 0;

    bool ret_val = SetSystemTime(ref st); // invoke this method.
}

but my ststem time after these codes is : 6 : 20 AM.
what is the problem and how can i fix it?

EDIT :
MY UTC IS : (UTC) Dublin, Edinburgh, Lisbon, London