Insert User and Date is a Google Docs™ addon that inserts an identifier for the user (username) and the current date (ISO yyyy-mm-dd format in the user's web browser's time zone) in square brackets at the cursor and leaves the cursor immediately after the insertion so the user can continue to type their entry. Users can optionally set an alias to use instead of their user name.
This is useful in shared docs where it is desired for specifically chosen author contributions to be immediately attributable, i.e. without having to search the version history.
[alanjl, 2022-08-25] Here is an example.