diff --git a/.gitignore b/.gitignore
index a88b536..b7d6fa6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
+.phpintel
 vendor/
-*.komodoproject
diff --git a/include/connect.php b/include/connect.php
index 9808810..0add7e4 100644
--- a/include/connect.php
+++ b/include/connect.php
@@ -1,5 +1,5 @@
 <?php
-    require(dirname(__FILE__) . "/config.php");
+  require(dirname(__FILE__) . "/config.php");
 
 	$options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
 	$bdd = new PDO("mysql:host=$host;port=$port;dbname=$db", $user, $pass, $options);
diff --git a/include/functions.php b/include/functions.php
index c3da34d..8729365 100644
--- a/include/functions.php
+++ b/include/functions.php
@@ -1,5 +1,21 @@
 <?php
 
+  function getMigrationSchemas() {
+    return [ 0, 5 ];
+  }
+
+  function updateSchema($bdd, $newKey) {
+    if ($newKey === 0) {
+      $req_string = 'INSERT INTO `application` (sql_schema) VALUES (?)';
+    }
+    else {
+      $req_string = 'UPDATE `application` SET `sql_schema` = ?';
+    }
+
+    $req = $bdd->prepare($req_string);
+    $req->execute(array($newKey));
+  }
+
   function printError($str) {
     echo '<div class="alert alert-danger" role="alert">' . $str . '</div>';
   }
diff --git a/include/grids.php b/include/grids.php
index 9a7bb46..2af635d 100644
--- a/include/grids.php
+++ b/include/grids.php
@@ -119,8 +119,8 @@
     $phone = "";
     $online = 0;
     $enable = 1;
-    $start = "0000-00-00";
-    $end = "0000-00-00";
+    $start = NULL;
+    $end = NULL;
 
     $req = $bdd->prepare('INSERT INTO user (user_id, user_pass, user_mail, user_phone, user_online, user_enable, user_start_date, user_end_date)
                         VALUES (?, ?, ?, ?, ?, ?, ?, ?)');
@@ -154,6 +154,9 @@
     if ($field === 'user_pass') {
       $value = hashPass($value);
     }
+    else if (($field === 'user_start_date' || $field === 'user_end_date') && $value === '') {
+      $value = NULL;
+    }
 
     // /!\ SQL injection: field was checked with in_array function
     $req_string = 'UPDATE user SET ' . $field . ' = ? WHERE user_id = ?';
diff --git a/include/html/menu.php b/include/html/menu.php
index e95a7c9..295d56b 100644
--- a/include/html/menu.php
+++ b/include/html/menu.php
@@ -1,12 +1,12 @@
 <div class="col-md-6 col-md-offset-3">
   <nav class="navbar navbar-default">
-    
+
     <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
       <ul class="nav navbar-nav">
         <li <?php if(!isset($_GET['admin'])) echo 'class="active"'; ?>><a href="index.php">Configurations</a></li>
         <li <?php if(isset($_GET['admin'])) echo 'class="active"'; ?>><a href="index.php?admin">Administrator</a></li>
       </ul>
     </div>
-    
+
   </nav>
-</div>
\ No newline at end of file
+</div>
diff --git a/index.php b/index.php
index 569a8dc..c3744dd 100644
--- a/index.php
+++ b/index.php
@@ -8,7 +8,7 @@
   if(isset($_GET['logout'])){
     session_destroy();
     header("Location: .");
-    exit -1;
+    exit(-1);
   }
 
   // Get the configuration files ?
@@ -79,7 +79,7 @@
     if($data && passEqual($_POST['admin_pass'], $data['admin_pass'])) {
       $_SESSION['admin_id'] = $data['admin_id'];
       header("Location: index.php?admin");
-      exit -1;
+      exit(-1);
     }
     else {
       $error = true;
@@ -110,7 +110,7 @@
       if(isInstalled($bdd) == true) {
         printError('OpenVPN-admin is already installed. Redirection.');
         header( "refresh:3;url=index.php?admin" );
-        exit -1;
+        exit(-1);
       }
 
       // If the user sent the installation form
@@ -122,18 +122,26 @@
         if($admin_pass != $admin_repeat_pass) {
           printError('The passwords do not correspond. Redirection.');
           header( "refresh:3;url=index.php?installation" );
-          exit -1;
+          exit(-1);
         }
 
-        // Create the tables or die
-        $sql_file = dirname(__FILE__) . '/sql/import.sql';
-        try {
-          $sql = file_get_contents($sql_file);
-          $bdd->exec($sql);
-        }
-        catch (PDOException $e) {
-          printError($e->getMessage());
-          exit -1;
+        // Create the initial tables
+        $migrations = getMigrationSchemas();
+        foreach ($migrations as $migration_value) {
+          $sql_file = dirname(__FILE__) . "/sql/schema-$migration_value.sql";
+          try {
+            $sql = file_get_contents($sql_file);
+            $bdd->exec($sql);
+          }
+          catch (PDOException $e) {
+            printError($e->getMessage());
+            exit(1);
+          }
+
+          unlink($sql_file);
+
+          // Update schema to the new value
+          updateSchema($bdd, $migration_value);
         }
 
         // Generate the hash
@@ -143,7 +151,6 @@
         $req = $bdd->prepare('INSERT INTO admin (admin_id, admin_pass) VALUES (?, ?)');
         $req->execute(array($admin_username, $hash_pass));
 
-        unlink($sql_file);
         rmdir(dirname(__FILE__) . '/sql');
         printSuccess('Well done, OpenVPN-Admin is installed. Redirection.');
         header( "refresh:3;url=index.php?admin" );
@@ -154,7 +161,7 @@
         require(dirname(__FILE__) . '/include/html/form/installation.php');
       }
 
-      exit -1;
+      exit(-1);
     }
 
     // --------------- CONFIGURATION ---------------
diff --git a/install.sh b/install.sh
index ce00b4b..59a1637 100755
--- a/install.sh
+++ b/install.sh
@@ -31,6 +31,7 @@ done
 www=$1
 user=$2
 group=$3
+
 openvpn_admin="$www/openvpn-admin"
 
 # Check the validity of the arguments
@@ -237,7 +238,6 @@ cp "/etc/openvpn/"{ca.crt,ta.key} "./client-conf/windows/"
 bower --allow-root install
 chown -R "$user:$group" "$openvpn_admin"
 
-
 printf "\033[1m\n#################################### Finish ####################################\n"
 
 echo -e "# Congratulations, you have successfully setup OpenVPN-Admin! #\r"
diff --git a/installation/scripts/connect.sh b/installation/scripts/connect.sh
index 0d481ae..ace884b 100644
--- a/installation/scripts/connect.sh
+++ b/installation/scripts/connect.sh
@@ -10,9 +10,8 @@ remote_port_1=$(echap "$remote_port_1")
 bytes_received=$(echap "$bytes_received")
 bytes_sent=$(echap "$bytes_sent")
 
-
 # We insert data in the log table
-mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "INSERT INTO log (log_id, user_id, log_trusted_ip, log_trusted_port, log_remote_ip, log_remote_port, log_start_time, log_end_time, log_received, log_send) VALUES(NULL, '$common_name','$trusted_ip', '$trusted_port','$ifconfig_pool_remote_ip', '$remote_port_1', now(),'0000-00-00 00:00:00', '$bytes_received', '$bytes_sent')"
+mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "INSERT INTO log (log_id, user_id, log_trusted_ip, log_trusted_port, log_remote_ip, log_remote_port, log_start_time, log_end_time, log_received, log_send) VALUES(NULL, '$common_name','$trusted_ip', '$trusted_port','$ifconfig_pool_remote_ip', '$remote_port_1', now(),NULL, '$bytes_received', '$bytes_sent')"
 
 # We specify that the user is online
 mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE user SET user_online=1 WHERE user_id='$common_name'"
diff --git a/installation/scripts/disconnect.sh b/installation/scripts/disconnect.sh
index 300d446..bfa07fd 100644
--- a/installation/scripts/disconnect.sh
+++ b/installation/scripts/disconnect.sh
@@ -12,4 +12,4 @@ trusted_port=$(echap "$trusted_port")
 mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE user SET user_online=0 WHERE user_id='$common_name'"
 
 # We insert the deconnection datetime
-mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE log SET log_end_time=now(), log_received='$bytes_received', log_send='$bytes_sent' WHERE log_trusted_ip='$trusted_ip' AND log_trusted_port='$trusted_port' AND user_id='$common_name' AND log_end_time='0000-00-00 00:00:00'"
+mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -e "UPDATE log SET log_end_time=now(), log_received='$bytes_received', log_send='$bytes_sent' WHERE log_trusted_ip='$trusted_ip' AND log_trusted_port='$trusted_port' AND user_id='$common_name' AND log_end_time=NULL"
diff --git a/installation/scripts/login.sh b/installation/scripts/login.sh
index afc794c..baa18c4 100644
--- a/installation/scripts/login.sh
+++ b/installation/scripts/login.sh
@@ -6,7 +6,7 @@ username=$(echap "$username")
 password=$(echap "$password")
 
 # Authentication
-user_pass=$(mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -sN -e "SELECT user_pass FROM user WHERE user_id = '$username' AND user_enable=1 AND (TO_DAYS(now()) >= TO_DAYS(user_start_date) OR user_start_date='0000-00-00') AND (TO_DAYS(now()) <= TO_DAYS(user_end_date) OR user_end_date='0000-00-00')")
+user_pass=$(mysql -h$HOST -P$PORT -u$USER -p$PASS $DB -sN -e "SELECT user_pass FROM user WHERE user_id = '$username' AND user_enable=1 AND (TO_DAYS(now()) >= TO_DAYS(user_start_date) OR user_start_date IS NULL) AND (TO_DAYS(now()) <= TO_DAYS(user_end_date) OR user_end_date IS NULL)")
 
 # Check the user
 if [ "$user_pass" == '' ]; then
diff --git a/migration.php b/migration.php
new file mode 100644
index 0000000..2ddf2f9
--- /dev/null
+++ b/migration.php
@@ -0,0 +1,55 @@
+<?php
+
+  if (count($argv) !== 2) {
+    echo "Need the www base path as argument";
+    exit(0);
+  }
+
+  $www = $argv[1];
+
+  require("$www/include/config.php");
+  require("$www/include/connect.php");
+  require("$www/include/functions.php");
+
+  $migrations = getMigrationSchemas();
+
+  try {
+    $req = $bdd->prepare('SELECT `sql_schema` FROM `application` LIMIT 1');
+    $req->execute();
+    $data = $req->fetch();
+
+    $sql_schema = 0;
+    if ($data['sql_schema']) {
+      $sql_schema = $data['sql_schema'];
+    }
+  }
+  // Table does not exist
+  catch (Exception $e) {
+    $sql_schema = 0;
+  }
+
+  // For each migrations
+  foreach ($migrations as $migration_value) {
+
+    // Do the migration, we are behind the last schema
+    if ($sql_schema < $migration_value) {
+
+      // Create the tables or die
+      $sql_file = dirname(__FILE__) . "/sql/schema-$migration_value.sql";
+      try {
+        $sql = file_get_contents($sql_file);
+        $bdd->exec($sql);
+      }
+      catch (PDOException $e) {
+        printError($e->getMessage());
+        exit(1);
+      }
+
+      // Update schema to the new value
+      updateSchema($bdd, $migration_value);
+
+      echo "Moved to schema $migration_value";
+    }
+  }
+
+?>
diff --git a/sql/import.sql b/sql/schema-0.sql
similarity index 92%
rename from sql/import.sql
rename to sql/schema-0.sql
index 50d8be1..d64aae5 100644
--- a/sql/import.sql
+++ b/sql/schema-0.sql
@@ -1,3 +1,5 @@
+CREATE TABLE IF NOT EXISTS `application` ( `id` INT(11) AUTO_INCREMENT, `sql_schema` INT(11) NOT NULL, PRIMARY KEY (id) );
+
 CREATE TABLE IF NOT EXISTS `admin` (
   `admin_id` varchar(255) NOT NULL,
   `admin_pass` varchar(255) NOT NULL,
diff --git a/sql/schema-5.sql b/sql/schema-5.sql
new file mode 100644
index 0000000..a67cf2c
--- /dev/null
+++ b/sql/schema-5.sql
@@ -0,0 +1,9 @@
+CREATE TABLE IF NOT EXISTS `application` ( `id` INT(11) AUTO_INCREMENT, `sql_schema` INT(11) NOT NULL, PRIMARY KEY (id) );
+
+ALTER TABLE `user` CHANGE `user_start_date` `user_start_date` DATE NULL DEFAULT NULL;
+ALTER TABLE `user` CHANGE `user_end_date` `user_end_date` DATE NULL DEFAULT NULL;
+ALTER TABLE `log` CHANGE `log_end_time` `log_end_time` TIMESTAMP NULL DEFAULT NULL;
+
+UPDATE `user` SET `user_start_date` = NULL WHERE `user_start_date` = '0000-00-00';
+UPDATE `user` SET `user_end_date` = NULL WHERE `user_end_date` = '0000-00-00';
+UPDATE `log` SET `log_end_time` = NULL WHERE `log_end_time` = '0000-00-00';
diff --git a/update.sh b/update.sh
index 09a3629..0d147e9 100755
--- a/update.sh
+++ b/update.sh
@@ -30,7 +30,7 @@ user=$(ls -l "$www/include/config.php" | awk '{ print $3 }')
 group=$(ls -l "$www/include/config.php" | awk '{ print $4 }')
 
 
-rm -r "${www:?}/"{index.php,bower.json,.bowerrc,js,include/html,include/connect.php,include/functions.php,include/grids.php,css,vendor}
+rm -rf "${www:?}/"{index.php,bower.json,.bowerrc,js,include/html,include/connect.php,include/functions.php,include/grids.php,css,vendor}
 
 cp -r "$base_path/"{index.php,bower.json,.bowerrc,js,css} "$www"
 cp -r "$base_path/include/"{html,connect.php,functions.php,grids.php} "$www/include"
@@ -44,4 +44,10 @@ rm -f "/etc/openvpn/scripts/"{connect.sh,disconnect.sh,login.sh,functions.sh}
 cp "$base_path/installation/scripts/"{connect.sh,disconnect.sh,login.sh,functions.sh} "/etc/openvpn/scripts"
 chmod +x "/etc/openvpn/scripts/"{connect.sh,disconnect.sh,login.sh,functions.sh}
 
+echo "Processing database migration..."
+
+php "$base_path/migration.php" "$www"
+
+echo "Database migrations done."
+
 echo "OpenVPN-admin upgraded."