SetSystemTimeAdjustment disable clock adjust rather than changing the RTC clock rate

Question

I need to override w32tm to adjust the DateTime clock-rate in C#. When I call the kernel32 API:

SetSystemTimeAdjustment(ref dwTimeAdjustment, ref bTimeAdjustmentDisabled);

I get a return of true, indicating it worked, but when I read back the results with GetSystemTimeAdjustment, lpTimeIncrement = lpTimeAdjustment, and the lpTimeAdjustmentDisabled is true, when I passed false in, indicating the Set operation disabled the clock adjust, rather than changing the rate.

• I have successfully set the SE_SYSTEMTIME_NAME privilege. When I call SetSystemTimeAdjustment without setting the privilege, it returns false as expected, and has no change on the system (keeping the w32tm setting). When I set the privilege, it returns true, and changes the rate (overriding w32tm) but it always results in the adjust interval being 156250, rather than the value commanded.
• I have tried with w32tm stopped as well, to make sure it wasn't fighting. Same result.

---

The function call looks like this:

WinRTClk.SetClockRate(156123); // Test to see if the clock can be sped up.

Here is the class:

public static class WinRTClk

{

    public static UInt32 ClkInterval = 0;

    public static UInt32 ClkRate = 0;

    private static bool ClkAdjDisable = false;

    public static double RTC_Adj_Ratio()

    {

        GetClockRate();

        return ((double) ((Int64) ClkRate - ClkInterval)) / ClkInterval;

    }

    public static bool GetClockRate() { return GetSystemTimeAdjustment(ref ClkRate, ref ClkInterval, ref ClkAdjDisable); }

    public static bool SetClockRate(Int32 Offset)

    {

        GetClockRate(); // Update ClkInterval

        UInt32 NewRate = (UInt32) ((Int64) ClkInterval + Offset);

        bool Disable = false;

        return SetSystemTimeAdjustment(ref NewRate, ref Disable);

    }

    // https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimeadjustment

    [DllImport("kernel32.dll")]

    private static extern bool GetSystemTimeAdjustment(ref UInt32 TimeAdj, ref UInt32 ClkInc, ref bool AdjDisable);

    //https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-setsystemtimeadjustment

    [DllImport("kernel32.dll")]

    private static extern bool SetSystemTimeAdjustment(ref UInt32 TimeAdj, ref bool AdjDisable);

}

Answer 1

Try another definition:

[DllImport("kernel32.dll")]
private static extern bool SetSystemTimeAdjustment( UInt32 TimeAdj, bool AdjDisable);

And adjust the code.