select
  id,
  email_address,
  to_char(valid_from, 'YYYY-MM-DD HH:MI:SS') as valid_from,
  to_char(valid_to, 'YYYY-MM-DD HH:MI:SS') as valid_to
from users_log;

 id |   email_address   |     valid_from      |      valid_to
----+-------------------+---------------------+---------------------
  1 | jerry@outlook.com | 2017-06-30 05:21:00 | 2017-07-08 02:25:05
  2 | tom@yahoo.com     | 2017-06-30 05:22:00 | 2017-07-08 02:25:05
... abridged ...
  1 | jerry@yahoo.com   | 2017-07-11 02:25:05 |
  2 | tom@aol.com       | 2017-07-11 02:25:05 |
(8 rows)