Calculate created files' size

Quick note to self on calculating cumulative size of regular files created in a certain timeframe:

find . -type f -a \( ! -ctime +6 \) -a -ctime +5 \
       -a -xdev -a -exec du -b \{\} \; |
cut -f1 -s |
( sz=0; while read fsz; do sz=$((${sz}+${fsz})); done; echo ${sz} )

IN the ecample above it will add up sizes of files updated betwee 5 and 6 days ago. Mac OSX users remove the -b option.