ElevenClock is an Open Source app that provides a clock for Windows 11 secondary taskbars.
As of right now, Windows 11, is lacking a clock for secondary screen taskbars. This young developer decided to code ElevenClock; it is a simple app that provides the same functionality as any secondary taskbar clocks on Windows 10. The clock updates the time each second so that you won't see different times across your taskbars.
ElevenClock supports all system locales and time formats and shows in all displays except the primary one. ElevenClock works with dark and light themes and works with taskbars on the top of the screen. It will give the correct alignment and size on HiDPi displays (100%, 200%, 300%) AND on fractional HiDPI displays(125%, 150%, 175%, 250%, etc.). It will also work on mismatched monitors (Display1: 100%, Display2: 150%, Display3: 225%, etc.) and automatically adjust itself when connecting or disconnecting monitors.
Similar: How to Show Multiple Clocks on Windows How to Fix Incorrect Date or Time With Windows Clock How to Show Time Only on the Windows 10 Taskbar How to Remove the Clock From Windows 10 Taskbar