Authorization of stay - passport entry stamp vs I94

[user1235]

My parents have come to US on B2 visa. The officer has stamped in the passport and written inside the stamp where it says valid until as "3 months" but when I checked I 94 online, it says valid until 6 months date.

 

passport entry stamp: "3 months"

US Entry date: 06/1/2014

I94 Valid until date: 12/1/2014

 

 

So my question is can my parents stay until 6 months or only for 3 months and also do we need to get the entry in passport be updated so that it does not have any issue when they come next time

 

Please advice me

 

Thanks