Problem in age on a dates interval

Hi all,

I'm using PostgreSQL 7.3.3 on i386-pc-linux-gnu, compiled by GCC gcc 
(GCC) 3.3 (Debian), and I don't understand the results of the following 
queries:


SELECT age('2004-05-14 16:00'::timestamp,'2004-02-18 16:00'::timestamp);     age      
----------------2 mons 25 days

SELECT '2004-02-18 16:00'::timestamp+'2 mons 25 days'::interval;     ?column?      
---------------------2004-05-13 16:00:00

In this case, the age from 2004-05-14 16:00 to 2004-02-18 16:00 is 2 
mons 25 days, but if I add the age to the initial date, it returns one 
day less!?



SELECT age('2004-05-26 16:00'::timestamp,'2004-02-18 16:00'::timestamp);     age     
---------------3 mons 8 days

SELECT '2004-02-18 16:00'::timestamp+'3 mons 8 days'::interval;     ?column?      
---------------------2004-05-26 16:00:00

Here, the age between 2004-05-26 16:00 and 2004-02-18 16:00 is 3 mons 8 
days, and this interval added to the initial date gives the correct result!!

Best regards,
Luis Sousa