Interesting. It would appear that Windows and Perl disagree about the date when daylight savings time started. I assume you are using the Windows exe version of exiftool? If so, it uses Perl 5.8. Perhaps if I updated to a more recent version of Perl it would fix this. I will look into it. Until then, try shifting the filemodifydate back by one hour on these files with -filemodifydate-=1. There is no platform-independent way to set the create date in Perl, so exiftool can not do this. - Phil