Oneliner to count the total number of days spent on a git project

daysSpentOnGitProject.sh

GIT_USER="${1-`git config user.name`}"
GIT_BRANCH=${2-master}
OFFSET=${3-0}

DAYS=`git log --pretty=format:"%cd %an" $GIT_BRANCH  2> /dev/null | grep -i "$GIT_USER" | awk '{print $1,$2,$3}' | uniq | wc -l`

echo "$GIT_USER spent `expr $DAYS - $OFFSET` days (tops!) on this git project ($GIT_BRANCH branch)"