Question

How can I change the local system’s date & time programmatically with C#?

Answer 1

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.