How can I change the local system's date & time programmatically with C#?
Here is where I found the answer.
I have reposted it here to improve clarity.
Define this structure:
[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;
}
Add the following extern
method to your class:
[DllImport("kernel32.dll", SetLastError = true)]
public static extern bool SetSystemTime(ref SYSTEMTIME st);
Then call the method with an instance of your struct like this:
SYSTEMTIME st = new SYSTEMTIME();
st.wYear = 2009; // must be short
st.wMonth = 1;
st.wDay = 1;
st.wHour = 0;
st.wMinute = 0;
st.wSecond = 0;
SetSystemTime(ref st); // invoke this method.
You can use a call to a DOS command but the invoke of the function in the windows dll is a better way to do it.
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)]
public extern static void Win32GetSystemTime(ref SystemTime sysTime);
[DllImport("kernel32.dll", EntryPoint = "SetSystemTime", SetLastError = true)]
public extern static bool Win32SetSystemTime(ref SystemTime sysTime);
private void button1_Click(object sender, EventArgs e)
{
// Set system date and time
SystemTime updatedTime = new SystemTime();
updatedTime.Year = (ushort)2009;
updatedTime.Month = (ushort)3;
updatedTime.Day = (ushort)16;
updatedTime.Hour = (ushort)10;
updatedTime.Minute = (ushort)0;
updatedTime.Second = (ushort)0;
// Call the unmanaged function that sets the new date and time instantly
Win32SetSystemTime(ref updatedTime);
}
Both require that the caller has been granted SeSystemTimePrivilege and that this privilege is enabled.
A lot of great viewpoints and approaches are already here, but here are some specifications that are currently left out and that I feel might trip up and confuse some people.
SetSystemTime
function. The reason is that calling process needs the SE_SYSTEMTIME_NAME privilege.SetSystemTime
function is expecting a SYSTEMTIME
struct in coordinated universal time (UTC). It will not work as desired otherwise. Depending on where/ how you are getting your DateTime
values, it might be best to play it safe and use ToUniversalTime()
before setting the corresponding values in the SYSTEMTIME
struct.
Code example:
DateTime tempDateTime = GetDateTimeFromSomeService();
DateTime dateTime = tempDateTime.ToUniversalTime();
SYSTEMTIME st = new SYSTEMTIME();
// All of these must be short
st.wYear = (short)dateTime.Year;
st.wMonth = (short)dateTime.Month;
st.wDay = (short)dateTime.Day;
st.wHour = (short)dateTime.Hour;
st.wMinute = (short)dateTime.Minute;
st.wSecond = (short)dateTime.Second;
// invoke the SetSystemTime method now
SetSystemTime(ref st);
Since I mentioned it in a comment, here's a C++/CLI wrapper:
#include <windows.h>
namespace JDanielSmith
{
public ref class Utilities abstract sealed /* abstract sealed = static */
{
public:
CA_SUPPRESS_MESSAGE("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands")
static void SetSystemTime(System::DateTime dateTime) {
LARGE_INTEGER largeInteger;
largeInteger.QuadPart = dateTime.ToFileTimeUtc(); // "If your compiler has built-in support for 64-bit integers, use the QuadPart member to store the 64-bit integer."
FILETIME fileTime; // "...copy the LowPart and HighPart members [of LARGE_INTEGER] into the FILETIME structure."
fileTime.dwHighDateTime = largeInteger.HighPart;
fileTime.dwLowDateTime = largeInteger.LowPart;
SYSTEMTIME systemTime;
if (FileTimeToSystemTime(&fileTime, &systemTime))
{
if (::SetSystemTime(&systemTime))
return;
}
HRESULT hr = HRESULT_FROM_WIN32(GetLastError());
throw System::Runtime::InteropServices::Marshal::GetExceptionForHR(hr);
}
};
}
The C# client code is now very simple:
JDanielSmith.Utilities.SetSystemTime(DateTime.Now);
Use this function to change the time of system (tested in window 8)
void setDate(string dateInYourSystemFormat)
{
var proc = new System.Diagnostics.ProcessStartInfo();
proc.UseShellExecute = true;
proc.WorkingDirectory = @"C:\Windows\System32";
proc.CreateNoWindow = true;
proc.FileName = @"C:\Windows\System32\cmd.exe";
proc.Verb = "runas";
proc.Arguments = "/C date " + dateInYourSystemFormat;
try
{
System.Diagnostics.Process.Start(proc);
}
catch
{
MessageBox.Show("Error to change time of your system");
Application.ExitThread();
}
}
void setTime(string timeInYourSystemFormat)
{
var proc = new System.Diagnostics.ProcessStartInfo();
proc.UseShellExecute = true;
proc.WorkingDirectory = @"C:\Windows\System32";
proc.CreateNoWindow = true;
proc.FileName = @"C:\Windows\System32\cmd.exe";
proc.Verb = "runas";
proc.Arguments = "/C time " + timeInYourSystemFormat;
try
{
System.Diagnostics.Process.Start(proc);
}
catch
{
MessageBox.Show("Error to change time of your system");
Application.ExitThread();
}
}
Example: Call in load method of form setDate("5-6-92"); setTime("2:4:5 AM");
proc.Arguments = "/C Date:" + dateInYourSystemFormat;
This Is Work Function:
void setDate(string dateInYourSystemFormat)
{
var proc = new System.Diagnostics.ProcessStartInfo();
proc.UseShellExecute = true;
proc.WorkingDirectory = @"C:\Windows\System32";
proc.CreateNoWindow = true;
proc.FileName = @"C:\Windows\System32\cmd.exe";
proc.Verb = "runas";
proc.Arguments = "/C Date:" + dateInYourSystemFormat;
try
{
System.Diagnostics.Process.Start(proc);
}
catch
{
MessageBox.Show("Error to change time of your system");
Application.ExitThread();
}
}