Policy domain review

Hi all,
i installed TSM 6.3 at windows server 2008 r2 with external tape drive(with LTO 5 Tape), it works fine but i have problem which's:

* I create a policy domain called "P_TANMIA_SEQ" , inside it a management class called "STANDARD" , the archiving setting in that MC --->How many days is a file kept? 7 Days.

Now i should be there're only 7 days archiving days only but in fact i saw more than that now and delete it by my self,
So why TSM does not keep only 7 days?

Is there something wrong i did ?

Kindly support me.
Best Regards,
Hany