https://bugs.winehq.org/show_bug.cgi?id=53516
--- Comment #1 from François Gouget fgouget@codeweavers.com --- A test shows that the Windows time service (w32time) is not disabled on the TestBot VMs. It's actually set to "Manual" on Windows 7 to Windows 10 2004, and "Automatic (Delayed Start, Trigger Start)" on Windows 10 2009 and greater.
The TestBot already sets the time before running a task but that may not be accurate to the millisecond (depends on the time synchronization of the TestBot server, network delays, and process startup times). So if the time service ends up synchronizing the time while a test runs it may cause the time to jump a little bit forwards or backwards (if the offset is > 128 ms).
So this could be the cause of the unexpected WM_TIMECHANGE messages and may also mess with timing checks (see bug 53171).