CountdownFunction.sh

# Source: http://serverfault.com/a/532600
Floor () 
{ 
    DIVIDEND=${1};
    DIVISOR=${2};
    RESULT=$(( ( ${DIVIDEND} - ( ${DIVIDEND} % ${DIVISOR}) )/${DIVISOR} ));
    echo ${RESULT}
}
Timecount () 
{ 
    s=${1};
    HOUR=$( Floor ${s} 60/60 );
    s=$((${s}-(60*60*${HOUR})));
    MIN=$( Floor ${s} 60 );
    SEC=$((${s}-60*${MIN}));
    while [ $HOUR -ge 0 ]; do
        while [ $MIN -ge 0 ]; do
            while [ $SEC -ge 0 ]; do
                printf "%02d:%02d:%02d\033[0K\r" $HOUR $MIN $SEC;
                SEC=$((SEC-1));
                sleep 1;
            done;
            SEC=59;
            MIN=$((MIN-1));
        done;
        MIN=59;
        HOUR=$((HOUR-1));
    done
}