According to Robert Peirce  <bob@peirce-family.com.invalid>:

    You don't say *whose* RAW format you are discussing.

    Since your Mac (if it has OS-X) has a unix system lurking under
the pretty GUI interface, you can run exiftool, which is a free
command-line program running under perl -- which is included in OS-X.  

    I know that it can edit Nikon's NEF RAW format.  I don't know
which RAW format you use.

    To get a manual from it, simply type (in your "Terminal"
window):

    exiftool -h

It will normally rename the original file by adding "_original" to the
end of its name, and save the changed information in the original
filename.  But, if you are comfortable with what you are doing, y ou can
include "-overwrite_original" in the command line to the exiftool
program.  Note that they say:

======================================================================
Caution: This option should only be used if you already have separate
     backup copies of your image files.
======================================================================

    It also has the following, which may be the tool which you
particularly want:

======================================================================
    exiftool -DateTimeOriginal-='0:0:0 1:30:0' dir
         Adjust original date/time of all images in directory
         "dir" by subtracting one hour and 30 minutes.  (This is
         equivalent to "-DateTimeOriginal-=1.5".  See
         Image::ExifTool::Shift.pl for details.)
======================================================================

So, if you can figure out precisely how many years, months, days, hours,
minutes, and seconds the files are in error by, you can convert *all* of
them in a specific directory to the correct information, preserving the
time relationship between the various shots.  And -- this can be done
with a single command line no matter how many files are present.

    Note that there are typically several date/time stamps in the
file, usually all set to the same value.  You might have to find the
names of the others as used in your camera's exif data to convert all of
the date/time stamps at the same time.  In the Nikon D70 exif
information, I find the following dates:

======================================================================
File Modification Date/Time     : 2007:03:02 02:02:06
Modify Date                     : 2007:03:02 02:02:06
Date/Time Original              : 2007:03:02 02:02:06
Create Date                     : 2007:03:02 02:02:06
Date/Time Original              : 2007:03:02 02:02:06.00
======================================================================

To get the actual tag names, instead of the human-friendly descriptions,
you will need to add the '-s' option:

======================================================================
%exiftool -s DSC_0324.JPG | grep -i 'date'
FileModifyDate                  : 2007:03:02 02:02:06
ModifyDate                      : 2007:03:02 02:02:06
DateTimeOriginal                : 2007:03:02 02:02:06
CreateDate                      : 2007:03:02 02:02:06
SubSecDateTimeOriginal          : 2007:03:02 02:02:06.00
======================================================================

The 'grep' is to eliminate all the output except the ones having "date"
in them, with the "-i" (ignore case", allowing you to find the date
strings whether mixed case or all lower case.  It looks as though I
could have avoided needing the "-i" on this by changing the command line
to:

    exiftool -s DSC_0324.JPG | grep 'Date'

had I been sure at the start that all tags would have the 'D' upper case
and the rest lower case.

    Anyway -- you will need to know the exact spelling of the tags
to be able to command changing them, which is why I showed you the way
to do this.

    You will also discover that exiftool will tell you how many
shots your shutter has taken in the Nikon cameras at least.

    I don't know whether 'exiftool' comes bundled with OS-X, but if
not you can download it and install it.  A quick web search should find
it for you -- it is also free, and will compile on any system with perl
installed, which includes the OS-X on the mac.

    I hope that this helps,
        DoN.