How to preserve timestamp using stat and touch

find dir -name '*.xml' -exec bash -c 't=$(stat -c %y "$0"); sed -i -e "s/text1/text2/g" "$0"; touch -d "$t" "$0"' {} \;

or

find dir -name '*.xml' -exec bash -c 'cp -p "$0" tmp; sed -i -e "s/text1/text2/g" "$0"; touch -r tmp "$0"' {} \;