Issue #19727: os.utime(..., None) is now potentially more precise under Windows.

Misc/NEWS

@@ -68,6 +68,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #19727: os.utime(..., None) is now potentially more precise
+  under Windows.
+
 - Issue #17201: ZIP64 extensions now are enabled by default.  Patch by
   William Mallard.
 

Modules/posixmodule.c

@@ -4953,13 +4953,8 @@ posix_utime(PyObject *self, PyObject *args, PyObject *kwargs)
     }
 
     if (utime.now) {
-        SYSTEMTIME now;
-        GetSystemTime(&now);
-        if (!SystemTimeToFileTime(&now, &mtime) ||
-            !SystemTimeToFileTime(&now, &atime)) {
-            PyErr_SetFromWindowsErr(0);
-            goto exit;
-        }
+        GetSystemTimeAsFileTime(&mtime);
+        atime = mtime;
     }
     else {
         time_t_to_FILE_TIME(utime.atime_s, utime.atime_ns, &atime);