Modifying Exif Data in Canon RAW (CR2) Files

I just got back from Israel and have about 1,200 pictures with an EST (UTC-5) timestamp that should have an IST (UTC+2) timestamp because I forgot to change my camera’s time. There’s a utility called ExifTool that can read and write the Exif (Exchangeable Image File) format embedded in the Canon Raw images with CR2 extensions. It’s available on Ubuntu in the libimage-exiftool-perl package. To change the dates, run
exiftool -AllDates+=HH:MM FILES.CR2.
In my case, my camera’s clock was 16 minutes fast and I had to shift the time ahead by seven hours, so I used
exiftool -AllDates+=6:44 *.CR2

This renamed each file to file.CR2_original and replaced the original with the updated Exif data. Unfortunately, the new file has the current modification time. I should have used the -P option. To fix this, I ran (in Bash):
for FILE in *.CR2; do touch -r ${FILE}_original ${FILE}; done

Alternately, I could have had Exiftool not rename the originals, but put the updated copies in another directory:
exiftool -P -AllDates+=6:44 -o ../from-camera-with-corrected-times *.CR2