select
t_add_date,
SUBSTRING(t_add_date :: character varying, 1, 19)
from table
where
t_add_date & lt;
NOW() - '1 DAY' :: interval t_add_date substring
2010-03-10 21:26:49.928445 2010-03-10 21:26:49
2010-03-10 21:26:49.928445 2010-03-10 21:26:49