Binary encoding of TIMESTAMP WITH TIME ZONE

[Joe Abbate]

I'm dealing with an issue where a query uses 'today'::date to select one 
of a number of rows depending on the day modulo the number of rows. The 
intent is that different information will be shown starting after 
midnight local time.  The query runs as expected in psql and using psycopg2.

However, when using the same query using the Rust adapter the transition 
to a new row started showing up after midgnight GMT.  I opened an issue 
on Github (https://github.com/sfackler/rust-postgres/issues/608 ) and 
the maintainer claimed the Rust adapter *had* to initialize timezone to 
UTC in order to properly convert "to and from time datatypes".  I 
pointed out that the timezone offset is available in psql and psycopg2, 
but then he replied the binary encoding of timestamptz does *not* 
include the timezone offset.

He pointed me to the function timestamptz_send() which per the comments 
"converts timestamptz to binary format".  I found that the TimestampTz 
used in the function is a typedef for an int64, but since I'm not 
familiar with the code, I can't tell if timezone offset is embedded in 
there or not.

I'm hoping someone reading this can confirm (or deny) the above (or do I 
need to ask the -hackers list?).

Regards,

Joe