Might want to make a note that the current behavior does not match the latest standard, but does match previous editions and/or RFC 3339.
We have such a note - it even gets printed in a big blue box.
"""
ISO 8601 specifies the use of uppercase letter T to separate the date and time. PostgreSQL accepts that format on input, but on output it uses a space rather than T, as shown above. This is for readability and for consistency with RFC 3339 as well as some other database systems.
