EXIF Date Change -Multiple

[hpolack]

I want to change the date only and not modify the time for multiple pictures. When I look at the options, it looks like you modify all the right dates (Date Taken, Date Digitized,etc), but it wants to update the time at the same time. I also would just like to change the AM or PM or in other words someone setup my camera for am instead of PM so when I took pictures it took them 12 hours earlier or later than it should of and caused some pictures to be saved on to my computer into the next day when I took them just afternoon.

So I want to modify am pm and date and change nothing else. Any chance? I can manually edit all the photos using Cam2PC pic by pic and just change these dates, but batch would be quicker.