TIMESTAMP vs TIMESTAMP WITHOUT TIME ZONE

Hello,

I have question about functionality for TIMESTAMP (with/without time zone).
The main question is, what is better for usage: timemestamp WITH or WITHOUT
time zone?

I have e.g. server in USA and there is 6:00 a.m. Then I have client somwhere in
Europe (+7 hour) and I read timestamp from server in USA.

Figure 1: (using pure TIMESTAMP type)
-------------------------------------
If I have defined column as:
my_date TIMESTAMP
and then I read current timestamp from the server (in USA) - it means I will use
LOCALTIMESTAMP, I will receive at the client computer current timestamp value
from USA - e.g. 10:00 a.m. But in the Europe is time 17:00 (+ 7 hour) and maybe
this can cause problems.

Figure 2: (using pure TIMESTAMP WITH TIME ZONE type)
----------------------------------------------------
If I have defined column as:
my_date TIMESTAMP WITH TIME ZONE
and then I read current timestamp from the server (in USA) - it means I will use
CURRENT_TIMESTAMP or now(). Then I will receive at the client computer current
timestamp value from USA - e.g. 10:00 a.m. and this timestamp will be
automatically convrerted to the correct time zone (17:00 in Europe) ? It means
when I send it back from europe client to the usa server, it will be also
automatically converted to the usa timestamp?

Is that right or I have didn't understand this behaviour? Is it better in
generally to use timestamp with time zone or timestamp without time zone?

Thanks for answer,
with best regards,

Julian Legeny

mailto:juleni(at)livetrade(dot)cz