Thanks, yes, found
http://www.exifer.friedemann.info/ &
http://www.photome.de/ &
http://www.amok.am/en/freeware/amok_exif_sorter/ &
http://www.sno.phy.queensu.ca/~phil/exiftool/ (all recommended by EXIF guru Friedemann Schmidt). Found that the date created in EXIF can be modified solely, leaving the rest of the binary data intact, unaltered.
I am the defendant. The claimant submitted a document with 1 picture... to accuse about a time/date of an event from the picture alone. I was curious whether we can request for the original jpeg file and get professional experts to retrieve the date from the EXIF. Then I find out that the EXIF date can easily be modified. I just wanted to experiement and try to find anyway to know if the EXIF has been modified. From my experiement, there's no way knowing.....