Microsoft is testing a change that removes the seconds display from the Calendar flyout in Windows 10, coinciding with the operating system's approaching end-of-support date in October. The update to build 19045.5737 includes bug fixes but strips away the clock feature for some users as part of an A/B testing phase. User reactions on platforms like Reddit indicate frustration over this change, which may be linked to the new Outlook application introduced earlier this year. Restoring the previous functionality requires technical skills in registry editing, and the new design is criticized for providing less information and having a visually unappealing layout. While Windows 11 still supports the seconds display, some Windows 10 users do not have this feature. Microsoft has also released a checklist advising Windows 10 users to consider upgrading their machines.