pdfcreatedate.sh

#!/bin/bash
# source: https://superuser.com/a/764524

# Managed formats:
# <xmp:CreateDate>2017-07-19T08:53:29Z</xmp:CreateDate>
# <xmp:CreateDate>2017-10-16T12:07:43+02:00</xmp:CreateDate>
# xmp:CreateDate="2013-09-03T17:37:08+02:00"

for f in *.pdf
do
  touch -t $(strings "$f" | grep 'xmp:CreateDate' | tail -1 | sed 's_.*xmp:CreateDate.\{1,2\}\(....\)-\(..\)-\(..\)T\(..\):\(..\):\(..\).*_\1\2\3\4\5.\6_g') "$f"
done