How do you remove the clock time from the menu bar in macOS?

Solution 1:

The clock is no longer optional for Big Sur and newer macOS. It drives the do not disturb shortcut (option + select) and summons the Notification Center when selected.

To minimize screen area, select the analog clock icon preference for the menu bar:

System Preferences > Dock & Menu Bar > Clock > Time Options > Analog

This is not what you want as per the title, as it removes the text of the time from the menu bar, but as per the question's description, it does set Big Sur notification to a single (clock) icon.

In terminal.app, this preference can be scripted or set from the command line:

defaults write com.apple.menuextra.clock IsAnalog -bool true

Solution 2:

There's no way to do it now because the time serves as the button for showing the notification center and the widget view. Hope it gets fixed in the future.