convert bash seconds to human readable hours minutes seconds

gistfile1.txt

displaytime () {
   local T=$SECONDS
   local D=$((T/60/60/24))
   local H=$((T/60/60%24))
   local M=$((T/60%60))
   local S=$((T%60))
   [[ $D > 0 ]] && printf '%d days ' $D
   [[ $H > 0 ]] && printf '%d hours ' $H
   [[ $M > 0 ]] && printf '%d minutes ' $M
   [[ $D > 0 || $H > 0 || $M > 0 ]] && printf 'and '
   printf '%d seconds\n' $S
}