timestamp with time zone

a.sql

example=# CREATE TABLE tstest (ts1 timestamp, ts2 timestamp with time zone);
CREATE TABLE
example=# \d tstest;
              Table "public.tstest"
 Column |            Type             | Modifiers
--------+-----------------------------+-----------
 ts1    | timestamp without time zone |
 ts2    | timestamp with time zone    |

example=# INSERT INTO tstest VALUES (current_timestamp, current_timestamp);
INSERT 0 1
example=# SELECT * FROM tstest;
            ts1             |              ts2
----------------------------+-------------------------------
 2014-07-19 23:11:38.230859 | 2014-07-19 23:11:38.230859+09
(1 row)

example=# INSERT INTO tstest VALUES (current_timestamp, '2014-07-19 23:12:00+08');
INSERT 0 1
example=# SELECT * FROM tstest;
            ts1             |              ts2
----------------------------+-------------------------------
 2014-07-19 23:11:38.230859 | 2014-07-19 23:11:38.230859+09
 2014-07-19 23:13:29.347091 | 2014-07-20 00:12:00+09
(2 rows)