Thanks, one follow up question

-The cutoff date for May is Aug. 1, 2002, so if your father's sister filed the I-130 on July 31, 2002 or earlier, then the priority date will be current in next month, May 2015. Otherwise, it is not current yet.

By the way, your parents can not stay in US longer than the I-94 expiration date unless they file I-485 before the I-94 expires.

Follow up question:

Their priority date was 8/2/2002 which is 1 day behind the current listing (what's the odd).
I know you said they cannot stay in US after I-94 (6/26/2015), but what if they can't get the current date by June, do I have to file B2 visa extension in June and then file 485 in July? From my understanding B2 visa ext takes 45 days, that means they will be out of status from 6/26/2015 - whenever b2 ext is granted.
Or, from some previous posts here, they can file 485 while in US regardless of their Visa Status or I might be mistaken here.
Thanks.