Displaying seconds as days/hours/mins/seconds?

function displaytime {

  local T=$1

  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

}