diff --git a/laravel/app/Http/Controllers/ReportController.php b/laravel/app/Http/Controllers/ReportController.php
index 76976878..39e7f0ac 100644
--- a/laravel/app/Http/Controllers/ReportController.php
+++ b/laravel/app/Http/Controllers/ReportController.php
@@ -60,7 +60,7 @@ public function searchUsers(Request $request)
 
         return json_encode($users);
     }
-
+    
     public function getDepartments(Request $request)
     {
         $id = $request->get('event');
diff --git a/laravel/app/Http/Controllers/SlotController.php b/laravel/app/Http/Controllers/SlotController.php
index 851a9e4e..3b17e841 100644
--- a/laravel/app/Http/Controllers/SlotController.php
+++ b/laravel/app/Http/Controllers/SlotController.php
@@ -66,7 +66,7 @@ public function view(Request $request, Slot $slot)
             $request->session()->flash('error', "You must enter your name before you can sign up for shifts.");
             return redirect('/profile/data/edit');
         }
-
+        
         return view('pages/slot/view', compact('slot'));
     }
 
@@ -101,6 +101,12 @@ public function take(SlotRequest $request, Slot $slot)
         // Has somebody else already taken this slot?
         if(is_null($slot->user))
         {
+            $concurrent_slot_warning = $this->warnIfConcurrentSlotForUserExists($request, $slot, Auth::user());
+            if($concurrent_slot_warning)
+            {
+                return back();
+            }
+
             $slot->user_id = Auth::user()->id;
             $slot->save();
 
@@ -167,7 +173,7 @@ public function adminRelease(Request $request, Slot $slot)
     {
         if(!is_null($slot->user))
         {
-            $username = Helpers::displayName($slot->user);
+            $user_name = Helpers::displayName($slot->user);
 
             $slot->user_id = null;
             $slot->save();
@@ -185,15 +191,63 @@ public function adminAssign(Request $request, Slot $slot)
     {
         $user = User::findorFail($request->get('user'));
 
+        $user_name = Helpers::displayName($user, false);
+
         if(is_null($slot->user))
         {
-            $username = Helpers::displayName($user);
+            $concurrent_slot_warning = $this->warnIfConcurrentSlotForUserExists($request, $slot, $user, true);
+            if($concurrent_slot_warning)
+            {
+                return back();
+            }
 
             $slot->user_id=$user->id;
             $slot->save();
             event(new SlotChanged($slot, ['status' => 'taken', 'admin_assigned' => true, 'name' => $user->name, 'email' => $user->email]));
-            $request->session()->flash('success', 'You added '.$username.' to this shift');
+            $request->session()->flash('success', 'You added '.$user_name.' to this shift');
         }
         return redirect('/event/'.$slot->event->id);
     }
+
+    /**
+     * Give a warning, if one hasn't already been delivered, to the client if a
+     * the user is trying to sign up or an admin is attempting to sign a user
+     * up for a slot one that overlaps with another slot the user is assigned
+     * to.
+     *
+     * @param  Request $request the client request
+     * @param  Slot    $slot    a currently unoccupied slot
+     * @param  User    $user    the user that will fill the slot
+     * @param  boolean $admin   whether or not this an admin request
+     * @return Response         a warning response or null
+     */
+    private function warnIfConcurrentSlotForUserExists(Request $request, Slot $slot, User $user, $admin=false)
+    {
+        //search for all user occupied slots that are concurrent with the given one
+        $concurrent_slot = Slot::where('user_id', $user->id)
+                                ->where('start_date', $slot->start_date)
+                                ->where('start_time', '<', $slot->end_time)
+                                ->where('end_time', '>', $slot->start_time)
+                                ->first();
+
+        //check if an overlapping slot for the user exists
+        if($concurrent_slot)
+        {
+            //check if the client has already been warned that the user has a concurrent slot
+            if(intval($request->input('concurrent-slot-warning-user-id')) !== $user->id)
+            {
+                $request->session()->flash('warning', [
+                    'layout' => 'concurrent-slot',
+                    'user' => $user,
+                    'slot' => $slot,
+                    'admin' => $admin,
+                    'user_id' => $user->id,
+                    'user_name' => Helpers::displayName($user, false),
+                    'concurrent_slot_id' => $concurrent_slot->id
+                ]);
+                return true;
+            }
+        }
+        return false;
+    }
 }
diff --git a/laravel/database/factories/ScheduleFactory.php b/laravel/database/factories/ScheduleFactory.php
index 10bfe2ed..cb2016be 100644
--- a/laravel/database/factories/ScheduleFactory.php
+++ b/laravel/database/factories/ScheduleFactory.php
@@ -2,6 +2,8 @@
 
 use App\Models\Department;
 use App\Models\Event;
+use App\Models\EventRole;
+use App\Models\Role;
 use App\Models\Schedule;
 use App\Models\Shift;
 use Carbon\Carbon;
@@ -54,6 +56,10 @@
             return $duration->format('H:i:s');
         },
         'volunteers' => $faker->numberBetween($volunteer_min, $volunteer_max),
+        'dates' => function($schedule)
+        {
+            return json_encode([$schedule['start_date'], $schedule['end_date']]);    
+        },
         'department_id' => function ($schedule)
         {
             $event_id = function () use ($schedule)
@@ -77,3 +83,21 @@
         },
     ];
 });
+
+$factory->afterCreating(Schedule::class, function(Schedule $schedule, Faker $faker) 
+{
+        //find the admin role
+        $volunteer_role = Role::where('name', 'volunteer')->first();
+        //if there is no admin role, create it
+        if (!$volunteer_role)
+        {
+            $volunteer_role = factory(Role::class)->create([
+                'name' => 'volunteer',
+            ]);
+        }
+    
+        $schedule->roles()->save(factory(EventRole::class)->make([
+            'role_id' => $volunteer_role->id,
+            'foreign_id' => $schedule->id,
+        ]));
+});
\ No newline at end of file
diff --git a/laravel/database/factories/UserFactory.php b/laravel/database/factories/UserFactory.php
index 52c3828d..e8410623 100644
--- a/laravel/database/factories/UserFactory.php
+++ b/laravel/database/factories/UserFactory.php
@@ -12,7 +12,25 @@
         'name' => $faker->unique()->userName,
         'email' => $faker->unique()->safeEmail,
         'password' => bcrypt($faker->password),
-  ];
+    ];
+});
+
+$factory->afterCreating(User::class, function (User $user, Faker $faker)
+{
+    //find the volunteer role
+    $volunteer_role = Role::where('name', 'volunteer')->first();
+    //if there is no volunteer role, create it
+    if (!$volunteer_role)
+    {
+        $volunteer_role = factory(Role::class)->create([
+            'name' => 'volunteer',
+        ]);
+    }
+
+    $user->roles()->save(factory(UserRole::class)->make([
+        'role_id' => $volunteer_role->id,
+        'user_id' => $user->id,
+    ]));
 });
 
 $factory->afterCreatingState(User::class, 'admin', function (User $user, Faker $faker)
diff --git a/laravel/resources/views/app.blade.php b/laravel/resources/views/app.blade.php
index b0cb1eb9..cd25a59a 100644
--- a/laravel/resources/views/app.blade.php
+++ b/laravel/resources/views/app.blade.php
@@ -33,6 +33,16 @@
                 </div>
             @endif
 
+            @if(Session::has('warning'))
+                <div class="general-alert alert alert-warning" role="alert">
+                    @if(isset(Session::get('warning')['layout']))
+                        <b>Warning!</b> @include('partials.warning.'.Session::get('warning')['layout'], Session::get('warning'))
+                    @else
+                        <b>Warning!</b> {{ Session::get('warning') }}
+                    @endif
+                </div>
+            @endif
+
             @if(Session::has('error'))
                 <div class="general-alert alert alert-danger" role="alert">
                     <b>Error!</b> {{ Session::get('error') }}
diff --git a/laravel/resources/views/pages/slot/view.blade.php b/laravel/resources/views/pages/slot/view.blade.php
index aecd875e..da336225 100644
--- a/laravel/resources/views/pages/slot/view.blade.php
+++ b/laravel/resources/views/pages/slot/view.blade.php
@@ -163,6 +163,7 @@
                 Please arrive at least 15 minutes ahead of time to be briefed by the previous shift team and answer any questions you have.
             </p>
 
+            <input type="hidden" name="concurrent-slot-warning-user-id" value="{{ Session::get('warning')['user_id'] }}">
             <button type="submit" class="btn btn-success">Take Shift</button>
         @endif
 
diff --git a/laravel/resources/views/partials/warning/concurrent-slot.blade.php b/laravel/resources/views/partials/warning/concurrent-slot.blade.php
new file mode 100644
index 00000000..ab5e3137
--- /dev/null
+++ b/laravel/resources/views/partials/warning/concurrent-slot.blade.php
@@ -0,0 +1,11 @@
+<span>
+@if(isset($admin) && $admin === true)
+    {{ $user_name }} is currently signed up for another
+    <a href=" {{ env('SITE_URL') }} /slot/{{ $concurrent_slot_id }}/view">overlapping shift</a>.
+    Are you sure you want to sign them up for this shift?
+@else
+    You are currently signed up for another
+    <a href="{{ env('SITE_URL') }}/slot/{{ $concurrent_slot_id }}/view">overlapping shift</a>.
+    Are you sure you want to sign up for this shift?
+@endif
+</span>
diff --git a/laravel/tests/Feature/SlotControllerTest.php b/laravel/tests/Feature/SlotControllerTest.php
index 225284a2..012e7751 100644
--- a/laravel/tests/Feature/SlotControllerTest.php
+++ b/laravel/tests/Feature/SlotControllerTest.php
@@ -3,6 +3,7 @@
 namespace Tests\Feature;
 
 use App\Models\Slot;
+use App\Models\UserData;
 use App\Models\User;
 use Tests\TestCase;
 use Illuminate\Foundation\Testing\WithFaker;
@@ -10,6 +11,71 @@
 
 class SlotControllerTest extends TestCase
 {
+    use RefreshDatabase;
+
+    /**
+     * @test
+     *
+     * @return void
+     */
+    public function same_time_shift_warned_on_take()
+    {
+        // Given
+        $take_slot = factory(Slot::class)->create();
+        $view_slot = factory(Slot::class)->create([
+            'start_date' => $take_slot->start_date,
+            'start_time' => $take_slot->start_time,
+            'end_time' => $take_slot->end_time,
+        ]);
+        $user = factory(User::class)->create();
+        $user->data()->save(factory(UserData::class)->make());
+
+        $take_slot->user_id = $user->id;
+        $take_slot->save();
+
+        $this->actingAs($user);
+
+        // When
+        $response = $this->followingRedirects()->post("/slot/{$view_slot->id}/take");
+
+        // Then
+        $response->assertSee("You are currently signed up for another")
+                ->assertSee("overlapping shift");
+    }
+
+    /**
+     * @test
+     *
+     * @return void
+     */
+    public function same_time_shift_warned_on_admin_assign()
+    {
+        // Given
+        $take_slot = factory(Slot::class)->create();
+        $view_slot = factory(Slot::class)->create([
+            'start_date' => $take_slot->start_date,
+            'start_time' => $take_slot->start_time,
+            'end_time' => $take_slot->end_time,
+        ]);
+        $user = factory(UserData::class)->create()->user;
+        $admin = factory(UserData::class)->create([
+            'user_id' => factory(User::class)->states('admin')->create()->id,
+        ])->user;
+
+        $this->actingAs($admin);
+
+        // When
+        $take_slot->user_id = $user->id;
+        $take_slot->save();
+
+        $response = $this->followingRedirects()->post("/slot/{$view_slot->id}/adminAssign", [
+            'user' => $user->id,
+        ]);
+
+        // Then
+        $response->assertSee("Are you sure you want to sign them up for this shift?");
+    }
+
     /**
      * @test
      * @return void
diff --git a/laravel/tests/Unit/ExampleTest.php b/laravel/tests/Unit/ExampleTest.php
index ebafacd6..4b4c86ed 100644
--- a/laravel/tests/Unit/ExampleTest.php
+++ b/laravel/tests/Unit/ExampleTest.php
@@ -10,7 +10,7 @@
 class ExampleTest extends TestCase
 {
     //Use this to clear the database at the beginning of the test class
-    use RefreshDatabase;
+    // use RefreshDatabase;
 
     /**
      * Make sure to use either "test" in the method name