24 hour while loop in bash

ping-test.sh

#!/bin/bash

## Script start time
START=$(date +%s)

## Total run time
DURRATION=$((60 * 60 * 24))

## Total running time
UPTIME=$(($(date +%s) - $START))

while [[ $UPTIME < $DURRATION ]]; do

    ## Logic here...
    echo -n "Time remaining: "
    echo $(($DURRATION - $UPTIME))

    ## Sleep for a bit
    sleep 2

    ## Update running time
    UPTIME=$(($(date +%s) - $START))

done