change raspberry pi volume follow the time one day

volume.sh

num=$(date "+%H")
t=$(date "+%F %T")
echo $num
if [ $num -le 5 ];then
        amixer set PCM,0 80%
        echo "$t ---> 60" >> /tmp/1.log
elif [ $num -gt 5 ]&&[ $num -lt 9 ];then
        amixer set PCM,0 86%
        echo "$t ---> 70" >> /tmp/1.log
elif [ $num -ge 9 ]&&[ $num -lt 13 ];then
        amixer set PCM,0 94%
        echo "$t ---> 80" >> /tmp/1.log
elif [ $num -ge 13 ]&&[ $num -lt 17 ];then
        amixer set PCM,0 97%
        echo "$t ---> 90" >> /tmp/1.log
elif [ $num -ge 17 ]&&[ $num -lt 21 ];then
        amixer set PCM,0 94%
        echo "$t ---> 80" >> /tmp/1.log
else [ $num -ge 21 ]&&[ $num -lt 23 ]
        amixer set PCM,0 86%
        echo "$t ---> 60" >> /tmp/1.log
fi