d=2015-01-01 while [ "$d" != 2015-02-20 ]; do echo $d d=$(date -I -d "$d + 1 day") # mac option for d decl (the +1d is equivalent to + 1 day) # d=$(date -j -v +1d -f "%Y-%m-%d" "2020-12-12" +%Y-%m-%d) done