postgres entre fechas
SELECT
user_id
FROM
user_logs
WHERE
login_date >= '2014-02-01'
AND login_date < '2014-03-01'
postgresql diferencia entre dos fechas en días
SELECT
AGE('2012-03-05', '2010-04-01'),
DATE_PART('year', AGE('2012-03-05', '2010-04-01')) AS years,
DATE_PART('month', AGE('2012-03-05', '2010-04-01')) AS months,
DATE_PART('day', AGE('2012-03-05', '2010-04-01')) AS days;
...
-- This will give you full years, month, days ... between two dates:
-- age | years | months | days
-- -----------------------+-------+--------+------
-- 1 year 11 mons 4 days | 1 | 11 | 4
postgresql obtener la diferencia entre dos fechas
select age('2010-04-01', '2012-03-05'),
date_part('year',age('2010-04-01', '2012-03-05')),
date_part('month',age('2010-04-01', '2012-03-05')),
date_part('day',age('2010-04-01', '2012-03-05'));