Since macOS Sonoma it is possible to display a large clock on the login screen of your Mac. You can also make the time appear prominently in the screen while running the screen saver.
Maybe you don’t want this, so as a Mac user you have the option to hide the clock on the login screen and/or screen saver. This will create more space for your background or screen saver, but the login window will remain at the bottom.
Hide clock login screen Mac
- Open  ▸ System Settings
- Go to ‘Access screen’
- Click the drop-down menu next to ‘Show large clock’
- Make a desired choice
Choose whether you want the current time to appear on the screen saver and the Lock screen, only on the Lock screen, or on neither. Your choice is automatically saved and applied immediately. You can check it immediately by locking the screen via  ▸ Lock screen. The login screen will then be displayed automatically.