Default TIME ZONE in functions

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/7.4/static/functions-formatting.html
Description:

I find the date-time functions Table 9-20 and operators Table 9-29
discussions incomplete in specifying how time zones are handled on inputs
and outputs, so that there are many ambiguities when trying to use these
functions and know exactly what TZ the inputs are interpreted as or implied
and converted to. This page
https://www.postgresql.org/docs/7.4/static/functions-formatting.html has no
mention of time zone in to_date and to_timestamp. Page
https://www.postgresql.org/docs/9.6/static/functions-datetime.html does not
explain what date and timestamp conversion on a string assume for time zone.
In general things work as expected but Ive encountered treacherous cases
where what happens is unexpected because of this lack of clarity.