lock screen clock

The lock screen clock in Windows can display time that is up to 30 seconds behind the real minute, and Microsoft confirms this behavior is by design. This lag only affects the secure desktop path used during boot, initial sign-in, and Ctrl+Alt+Delete, not the ordinary lock screen accessed via Windows key + L. The time is correct in the kernel, but the screen refreshes on a fixed interval that can drift from the minute boundary. Microsoft's support guidance distinguishes the logon experience from the user-session lock screen, which uses a different display mechanism.