MariaDB [RaspyDB]> DESC TemperatureLOG;
+---------+-------------+------+-----+---------+-------+
| Field   | Type        | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| TimeLog | datetime    | NO   | MUL | NULL    |       |

#!/bin/bash
source /var/www/script/QUERY/configLogin.cnf

DB_USER=$user >&2
DB=$DB >&2
DB_PASS=$pwd >&2
DB_IP=$IP >&2



query="select DATE_FORMAT(TimeLog, '%d/%m/%y %H:%i:%s') FROM TemperatureLOG order by TimeLog DESC LIMIT 1;"

tempVal=$(mysql -u "$DB_USER" --password="$DB_PASS" --host="$DB_IP" --database="$DB" --execute="$query" | awk 'NR==2{print $1,$2}')
echo "string  DB:$tempVal="


dataDB_tmp=${tempVal%% *}
echo "data_tmp DB:$dataDB_tmp"

d1DB=$(date -d "$tempVal" +'%m/%d/%y %T')
echo "data DB:$d1DB"

dataDB=$(date -d "$dataDB_tmp" +"%d/%m/%y");
echo "data DB:$dataDB"

timeDB=${tempVal##* }
echo "time DB:$timeDB"


currenttime=$(date +'%d/%m/%y %T')
echo "current time:$currenttime"

curDate=$(date +'%d/%m/%y')
echo "current data:$curDate"

curTime=$(date +'%T')
echo "current time:$curTime"
if [[ $D1db > $currenttime ]];
then
        echo "db minore current"
else
        echo "current maggiore db"
fi


echo $(( $currenttime - $D1db ))

val1=2013-12-31T00:00:00
val2=2014-11-19T15:40:30
if [[ $val1 < $val2 ]];
then
        echo $?
else
        echo $?
fi

echo $(( $val2 - $val1 )/(60*60*24))

MariaDB [RaspyDB]> select DATE_FORMAT(TimeLog, '%d/%m/%y %H:%i:%s') FROM TemperatureLOG order by TimeLog DESC LIMIT 1;
+-------------------------------------------+
| DATE_FORMAT(TimeLog, '%d/%m/%y %H:%i:%s') |
+-------------------------------------------+
| 10/12/19 14:21:40                         |
+-------------------------------------------+
1 row in set (0.01 sec)

MariaDB [RaspyDB]> select TimeLog FROM TemperatureLOG order by TimeLog DESC LIMIT 1;
+---------------------+
| TimeLog             |
+---------------------+
| 2019-12-10 14:23:41 |
+---------------------+
1 row in set (0.00 sec)

MariaDB [RaspyDB]>