4 files changed, 30 insertions, 7 deletions

diff --git a/docs/users.md b/docs/users.md
index 347bf6e..489ff59 100644
--- a/docs/users.md
+++ b/docs/users.md
@@ -30,7 +30,7 @@ echo 'Full name: '.$user->firstName.' '.$user->lastName."\n";
 
 ## Getting All Users
 
-You can use the `findUsers` method on the `Gatekeeper` class to get a list (returnes a `UserCollection`) of the current users:
+You can use the `findUsers` method on the `Gatekeeper` class to get a list (returns a `UserCollection`) of the current users:
 
 ```php
 $users = Gatekeeper::findUsers();
@@ -57,7 +57,7 @@ Gatekeeper::register($credentials);
 ```
 
 The return value from the `register` call is a *boolean* indicating the pass/fail status of the registration.
-Addiitonally, you can also link the user to permissions at create time:
+Additionally, you can also link the user to permissions at create time:
 
 ```php
 <?php
@@ -101,7 +101,7 @@ Gatekeeper::register($credentials);
 
 ## Removing users
 
-Deleteing user records can be done with the `deleteUserById` method:
+Deleting user records can be done with the `deleteUserById` method:
 
 ```php
 <?php
@@ -165,11 +165,20 @@ You can add a user to a group by using the group ID:
 <?php
 $groupId = 1;
 if (Gatekeeper::findUserById($userId)->addGroup($groupId) === true) {
-    echo "User added successfullly!";
+    echo "User added successfully!";
 }
 ?>
 ```
 
+You can also grant the group to a user with an expiration time, giving them permissions until a certain time. You set the expiration as a second value on the `addGroup` method by passing in a Unix timestamp:
+
+```php
+<?php
+if (Gatekeeper::findUserById(1)->addGroup(1, strtotime('+1 day')) === true) {
+    echo "User added successfully!";
+}
+```
+
 ## Revoking access to a group
 
 You can also remove a user from a group by revoking their access:
diff --git a/src/Psecio/Gatekeeper/GroupModel.php b/src/Psecio/Gatekeeper/GroupModel.php
index 899336b..5d7fe24 100644
--- a/src/Psecio/Gatekeeper/GroupModel.php
+++ b/src/Psecio/Gatekeeper/GroupModel.php
@@ -30,6 +30,11 @@ class GroupModel extends \Psecio\Gatekeeper\Model\Mysql
             'column' => 'name',
             'type' => 'varchar'
         ),
+        'expire' => array(
+            'description' => 'Expiration Date',
+            'column' => 'expire',
+            'type' => 'datetime'
+        ),
         'created' => array(
             'description' => 'Date Created',
             'column' => 'created',
diff --git a/src/Psecio/Gatekeeper/UserGroupModel.php b/src/Psecio/Gatekeeper/UserGroupModel.php
index a8451b3..4c3269e 100644
--- a/src/Psecio/Gatekeeper/UserGroupModel.php
+++ b/src/Psecio/Gatekeeper/UserGroupModel.php
@@ -30,6 +30,11 @@ class UserGroupModel extends \Psecio\Gatekeeper\Model\Mysql
             'column' => 'id',
             'type' => 'integer'
         ),
+        'expire' => array(
+            'description' => 'Expiration Date',
+            'column' => 'expire',
+            'type' => 'datetime'
+        ),
         'created' => array(
             'description' => 'Date Created',
             'column' => 'created',
diff --git a/src/Psecio/Gatekeeper/UserModel.php b/src/Psecio/Gatekeeper/UserModel.php
index 503fcf4..9389fb2 100644
--- a/src/Psecio/Gatekeeper/UserModel.php
+++ b/src/Psecio/Gatekeeper/UserModel.php
@@ -229,15 +229,19 @@ class UserModel extends \Psecio\Gatekeeper\Model\Mysql
      * @param integer|GroupModel $group Add the user to a group
      * @return boolean Success/fail of add
      */
-    public function addGroup($group)
+    public function addGroup($group, $expire = null)
     {
         if ($group instanceof GroupModel) {
             $group = $group->id;
         }
-        $group = new UserGroupModel($this->getDb(), array(
+        $data = [
             'group_id' => $group,
             'user_id' => $this->id
-        ));
+        ];
+        if ($expire !== null && is_int($expire)) {
+            $data['expire'] = $expire;
+        }
+        $group = new UserGroupModel($this->getDb(), $data);
         return $this->getDb()->save($group);
     }