start_time=$SECONDS
# ... do some work ...
total_seconds=$(( SECONDS - start_time ))

days=$(( total_seconds / 86400 ))
total_seconds=$(( total_seconds - ( 86400 * days ) ))
hour=$(( total_seconds / 3600 ))
total_seconds=$(( total_seconds - ( 3600 * hour ) ))
mins=$(( total_seconds / 60 ))
secs=$(( total_seconds - ( 60 * mins ) ))

printf "Days: %-6d\n" ${days}
printf "Hours: %-6d\n" ${hour}
printf "Minutes: %-6d\n" ${mins}
printf "Seconds: %-6d\n" ${secs}