"...add 1 to the month."

Update:

Well, i say $m_month += 1; but i still get 2015:01:07 14:46:51

karls-mac-mini:monks karl$ perl -MImage::ExifTool=:Public -E 'say Imag
+eInfo("./pdf/a.pdf")->{CreateDate};'
2015:02:07 14:46:51
karls-mac-mini:monks karl$ ls ./pdf/a.pdf 
-rw-r--r--@ 1 karl  karl    48K  7 Feb 14:46 ./pdf/a.pdf
[download]

Best regards, Karl