diff --git a/src/Controller/APIController.php b/src/Controller/APIController.php
index eec92bf7..050d1bc5 100644
--- a/src/Controller/APIController.php
+++ b/src/Controller/APIController.php
@@ -989,117 +989,209 @@ class APIController extends Controller implements LoggedController
         $invoice = $ic->generateInvoice($icrit);
         $jo->setInvoice($invoice);
 
-        // assign hub and rider
-        if (($jo->getServiceType() == ServiceType::BATTERY_REPLACEMENT_NEW) ||
-            ($jo->getServicetype() == ServiceType::BATTERY_REPLACEMENT_WARRANTY))
+        // check if advance order
+        // check for time when request came in
+        $request_time_in_int = time();
+        $start = '17:00';
+        $end = '08:00';
+
+        $start_time = strtotime($start);
+        $end_time = strtotime($end);
+
+        if (($request_time_in_int > $start_time) ||
+            (($request_time_in_int < $start_time) && ($request_time_in_int < $end_time)))
         {
-            // get nearest hub
-            // $nearest_hub = $this->findNearestHubWithInventory($jo, $batt, $em, $map_tools, $im);
-            $nearest_hub = $this->findNearestHub($jo, $em, $map_tools);
+            // advance order
+            // assign hub and rider
+            if (($jo->getServiceType() == ServiceType::BATTERY_REPLACEMENT_NEW) ||
+                ($jo->getServicetype() == ServiceType::BATTERY_REPLACEMENT_WARRANTY))
+            {
+                // get nearest hub
+                // $nearest_hub = $this->findNearestHubWithInventory($jo, $batt, $em, $map_tools, $im);
+                // TODO: when the inventory manager kicks in, create new function that finds the
+                // the nearest hub with inventory and rider slot
+                // convert to DateTime
+                $nearest_hub = $this->findAdvanceNearestHub($jo, $request_time_in_int, $em, $map_tools);
+            }
+            else
+            {
+                $nearest_hub = $this->findAdvanceNearestHub($jo, $request_time_in_int, $em, $map_tools);
+            }
+
+            if (!empty($nearest_hub))
+            {
+                $jo->setHub($nearest_hub);
+                $jo->setStatus(JOStatus::ASSIGNED);
+            }
+
+            $em->persist($jo);
+            $em->persist($invoice);
+
+            // add event log for JO
+            $event = new JOEvent();
+            $event->setDateHappen(new DateTime())
+                ->setTypeID(JOEventType::CREATE)
+                ->setJobOrder($jo);
+            $em->persist($event);
+
+            // check JO status
+            if ($jo->getStatus() == JOStatus::ASSIGNED)
+            {
+                // add event logs for hub and rider assignments
+                $hub_assign_event = new JOEvent();
+                $hub_assign_event->setDateHappen(new DateTime())
+                    ->setTypeID(JOEventType::HUB_ASSIGN)
+                    ->setJobOrder($jo);
+
+                $em->persist($hub_assign_event);
+            }
+
+            $em->flush();
+
+            // make invoice json data
+            $invoice_data = [
+                'total_price' => $invoice->getTotalPrice(),
+                'vat_ex_price' => $invoice->getVATExclusivePrice(),
+                'vat' => $invoice->getVAT(),
+                'discount' => $invoice->getDiscount(),
+                'trade_in' => $invoice->getTradeIn(),
+            ];
+            $items = $invoice->getItems();
+            $items_data = [];
+            foreach ($items as $item)
+            {
+                $items_data[] = [
+                    'title' => $item->getTitle(),
+                    'qty' => $item->getQuantity() + 0,
+                    'price' => $item->getPrice() + 0.0,
+                ];
+            }
+            $invoice_data['items'] = $items_data;
+
+            // make job order data
+            $data = [
+                'jo_id' => $jo->getID(),
+                'invoice' => $invoice_data
+            ];
+
+            // set data
+            $res->setData($data); 
+
         }
         else
         {
-            $nearest_hub = $this->findNearestHub($jo, $em, $map_tools);
-        }
-
-        if (!empty($nearest_hub))
-        {
-            // assign rider
-            $available_riders = $nearest_hub->getAvailableRiders();
-            if (count($available_riders) > 0)
+            // assign hub and rider
+            if (($jo->getServiceType() == ServiceType::BATTERY_REPLACEMENT_NEW) ||
+                ($jo->getServicetype() == ServiceType::BATTERY_REPLACEMENT_WARRANTY))
             {
-                $assigned_rider = null;
-                if (count($available_riders) > 1)
-                {
-                    // TODO: the setting of riders into an array
-                    //  will no longer be necessary when the contents
-                    // of randomizeRider changes
-                    $riders = [];
-                    foreach ($available_riders as $rider)
-                    {
-                        $riders[] = $rider;
-                    }
-
-                    $assigned_rider = $this->randomizeRider($riders);
-                }
-                else
-                    $assigned_rider = $available_riders[0];
-         
-                $jo->setHub($nearest_hub);
-                $jo->setRider($assigned_rider);
-                $jo->setStatus(JOStatus::ASSIGNED);
-
-                $assigned_rider->setAvailable(false);
+                // get nearest hub
+                // $nearest_hub = $this->findNearestHubWithInventory($jo, $batt, $em, $map_tools, $im);
+                $nearest_hub = $this->findNearestHub($jo, $em, $map_tools);
+            }
+            else
+            {
+                $nearest_hub = $this->findNearestHub($jo, $em, $map_tools);
             }
-        }
 
-        $em->persist($jo);
-        $em->persist($invoice);
+            if (!empty($nearest_hub))
+            {
+                // assign rider
+                $available_riders = $nearest_hub->getAvailableRiders();
+                if (count($available_riders) > 0)
+                {
+                    $assigned_rider = null;
+                    if (count($available_riders) > 1)
+                    {
+                        // TODO: the setting of riders into an array
+                        //  will no longer be necessary when the contents
+                        // of randomizeRider changes
+                        $riders = [];
+                        foreach ($available_riders as $rider)
+                        {
+                            $riders[] = $rider;
+                        }
 
-        // add event log for JO
-        $event = new JOEvent();
-        $event->setDateHappen(new DateTime())
-            ->setTypeID(JOEventType::CREATE)
-            ->setJobOrder($jo);
-        $em->persist($event);
+                        $assigned_rider = $this->randomizeRider($riders);
+                    }
+                    else
+                        $assigned_rider = $available_riders[0];
+         
+                    $jo->setHub($nearest_hub);
+                    $jo->setRider($assigned_rider);
+                    $jo->setStatus(JOStatus::ASSIGNED);
 
-        // check JO status
-        if ($jo->getStatus() == JOStatus::ASSIGNED)
-        {
-            // add event logs for hub and rider assignments
-            $hub_assign_event = new JOEvent();
-            $hub_assign_event->setDateHappen(new DateTime())
-                ->setTypeID(JOEventType::HUB_ASSIGN)
+                    $assigned_rider->setAvailable(false);
+                }
+            }
+
+            $em->persist($jo);
+            $em->persist($invoice);
+
+            // add event log for JO
+            $event = new JOEvent();
+            $event->setDateHappen(new DateTime())
+                ->setTypeID(JOEventType::CREATE)
                 ->setJobOrder($jo);
+            $em->persist($event);
 
-            $em->persist($hub_assign_event);
+            // check JO status
+            if ($jo->getStatus() == JOStatus::ASSIGNED)
+            {
+                // add event logs for hub and rider assignments
+                $hub_assign_event = new JOEvent();
+                $hub_assign_event->setDateHappen(new DateTime())
+                    ->setTypeID(JOEventType::HUB_ASSIGN)
+                    ->setJobOrder($jo);
 
-            $rider_assign_event = new JOEvent();
-            $rider_assign_event->setDateHappen(new DateTime())
-                ->setTypeID(JOEventType::RIDER_ASSIGN)
-                ->setJobOrder($jo);
+                $em->persist($hub_assign_event);
 
-            $em->persist($rider_assign_event);
+                $rider_assign_event = new JOEvent();
+                $rider_assign_event->setDateHappen(new DateTime())
+                    ->setTypeID(JOEventType::RIDER_ASSIGN)
+                    ->setJobOrder($jo);
 
-            // user mqtt event
-            $payload = [
-                'event' => 'outlet_assign'
+                $em->persist($rider_assign_event);
+
+                // user mqtt event
+                $payload = [
+                    'event' => 'outlet_assign'
+                ];
+                $mclient->sendEvent($jo, $payload);
+
+                $rah->assignJobOrder($jo, $jo->getRider());
+            }
+
+            $em->flush();
+
+            // make invoice json data
+            $invoice_data = [
+                'total_price' => $invoice->getTotalPrice(),
+                'vat_ex_price' => $invoice->getVATExclusivePrice(),
+                'vat' => $invoice->getVAT(),
+                'discount' => $invoice->getDiscount(),
+                'trade_in' => $invoice->getTradeIn(),
             ];
-            $mclient->sendEvent($jo, $payload);
+            $items = $invoice->getItems();
+            $items_data = [];
+            foreach ($items as $item)
+            {
+                $items_data[] = [
+                    'title' => $item->getTitle(),
+                    'qty' => $item->getQuantity() + 0,
+                    'price' => $item->getPrice() + 0.0,
+                ];
+            }
+            $invoice_data['items'] = $items_data;
 
-            $rah->assignJobOrder($jo, $jo->getRider());
-        }
-
-        $em->flush();
-
-        // make invoice json data
-        $invoice_data = [
-            'total_price' => $invoice->getTotalPrice(),
-            'vat_ex_price' => $invoice->getVATExclusivePrice(),
-            'vat' => $invoice->getVAT(),
-            'discount' => $invoice->getDiscount(),
-            'trade_in' => $invoice->getTradeIn(),
-        ];
-        $items = $invoice->getItems();
-        $items_data = [];
-        foreach ($items as $item)
-        {
-            $items_data[] = [
-                'title' => $item->getTitle(),
-                'qty' => $item->getQuantity() + 0,
-                'price' => $item->getPrice() + 0.0,
+            // make job order data
+            $data = [
+                'jo_id' => $jo->getID(),
+                'invoice' => $invoice_data
             ];
+
+            // set data
+            $res->setData($data); 
         }
-        $invoice_data['items'] = $items_data;
-
-        // make job order data
-        $data = [
-            'jo_id' => $jo->getID(),
-            'invoice' => $invoice_data
-        ];
-
-        // set data
-        $res->setData($data);
 
         return $res->getReturnResponse();
     }
@@ -2464,4 +2556,306 @@ class APIController extends Controller implements LoggedController
         return $selected_rider;
     }
 
+    protected function findAdvanceNearestHub($jo, $request_time, EntityManagerInterface $em, MapTools $map_tools)
+    {
+        // get the nearest 10 hubs
+        $selected_hub = null;
+        $hubs = $map_tools->getClosestOpenHubs($jo->getCoordinates(), 10);
+
+        $nearest_hubs_with_distance = [];
+        $nearest_branch_codes = [];
+        foreach ($hubs as $hub)
+        {
+            $nearest_hubs_with_distance[] = $hub;
+            //if (!empty($hub['hub']->getBranchCode()))
+            //    $nearest_branch_codes[] = $hub['hub']->getBranchCode();
+        }
+
+        // check if nearest hubs have branch codes
+        //if (count($nearest_branch_codes) == 0)
+        //    return $selected_hub;
+
+        // assume all 10 have stock
+        // find the nearest hub with available riders
+        $nearest = null;
+        $slot_found = false;
+        foreach ($nearest_hubs_with_distance as $nhd)
+        {
+            if (empty($nearest))
+                $nearest = $nhd;
+            else
+            {
+                if ($nhd['distance'] < $nearest['distance'])
+                $nearest = $nhd;
+            }
+
+            $result = $this->findRiderSlots($jo, $nearest['hub'], $request_time, $em);
+
+            if ($result != null)
+                $slot_found = $result['slot_found'];
+            else
+                $nearest = null; 
+        }
+
+        if ($slot_found && $nearest != null)
+        {
+            $result = $this->findRiderSlots($jo, $nearest['hub'], $request_time, $em);
+
+            if ($result != null)
+            {
+                $jo_date_schedule = $result['date_schedule'];
+
+                $jo->setAdvanceOrder(true);
+                $jo->setDateSchedule($jo_date_schedule);
+
+                $selected_hub = $nearest['hub'];
+            }
+
+        }
+
+        // uncomment this snippet when inventory check becomes active
+        // get battery sku
+        /*
+        if ($batt != null)
+        {
+            $skus[] = $batt->getSAPCode();
+
+            // api call to check inventory
+            // pass the list of branch codes of nearest hubs and the skus
+            // go through returned list of branch codes 
+            // bypass inventory check for now
+            // $hubs_with_inventory = $im->getBranchesInventory($nearest_branch_codes, $skus);
+            if (!empty($hubs_with_inventory))
+            {
+                $nearest = [];
+                $flag_hub_found = false;
+                foreach ($hubs_with_inventory as $hub_with_inventory)
+                {
+                    // find hub according to branch code
+                    $found_hub = $em->getRepository(Hub::class)->findOneBy(['branch_code' => $hub_with_inventory['BranchCode']]);
+                    if ($found_hub != null)
+                    {
+                        // check rider availability
+                        if (count($found_hub->getAvailableRiders()) > 0)
+                        {
+                            // check against nearest hubs with distance
+                            foreach ($nearest_hubs_with_distance as $nhd)
+                            {
+                                // get distance of hub from location, compare with $nearest. if less, replace nearest
+                                if ($found_hub->getID() == $nhd['hub']->getID())
+                                {
+                                    if (empty($nearest))
+                                    {
+                                        $nearest = $nhd;
+                                        $flag_hub_found = true;
+                                    }
+                                    else
+                                    {
+                                        if ($nhd['distance'] < $nearest['distance'])
+                                        {
+                                            $nearest = $nhd;
+                                            $flag_hub_found = true;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                $selected_hub = $nearest['hub'];
+            } 
+        } */
+        return $selected_hub;
+    }
+
+    protected function findRiderSlots($jo, Hub $hub, $request_time, EntityManagerInterface $em)
+    {
+        $flag_found_slot = false;
+        $results = [];
+
+        // array of # of riders that can handle JOs in a timeslot
+        $hub_rider_slots = [];
+
+        // populate the array with the hub's rider slots
+        for ($i = 0; $i <=7; $i++)
+        {
+            $hub_rider_slots[$i] = $hub->getRiderSlots();
+        }
+
+        // check hub's advance orders for the day
+        // get number of advance orders for the next day if request came in before midnight
+        // or for current day if request came in after midnight
+        // check request_time
+        $midnight = strtotime('00:00'); 
+        $start_date =  new DateTime();
+        $end_date = new DateTime(); 
+
+        if ($request_time < $midnight) 
+        {
+            // add +1 to date to start and end date
+            $start_date->add(new DateInterval('P1D'));
+            $end_date->add(new DateInterval('P1D'));
+        } 
+
+        // set time bounds for the start and end date
+        $start_date->setTime(0, 1);
+        $end_date->setTime(23, 59);
+
+        $str_request_time = date('Y-m-d H:i:s', $request_time);
+        $time_of_request = DateTime::createFromFormat('Y-m-d H:i:s', $str_request_time);
+
+        // NOTE: get advance orders via query
+        // get JOs assigned to hub that are advance orders and scheduled for the next day(if before midnight) or current day(if after midnight) with
+        // for hub assignment status
+        $query = $em->createQuery('select jo from App\Entity\JobOrder jo where jo.hub = :hub and jo.flag_advance = true and 
+                jo.date_schedule >= :date_start and jo.date_schedule <= :date_end and jo.status = :status');
+        $jos_advance_orders = $query->setParameters([
+                'hub' => $hub,
+                'date_start' => $start_date,
+                'date_end' => $end_date,
+                'status' => JOStatus::ASSIGNED,
+            ])
+           ->getResult();
+
+        // check each JO's date_schedule, decrement rider_slots if date schedule falls in that slot
+        // index - equivalent time
+        // 0 - 8-9
+        // 1 - 9-10
+        // 2 - 10-11
+        // 3 - 11-12
+        // 4 - 12 -13
+        // 5 - 13-14
+        // 6 - 14-15
+        // 7 - 15-16
+        foreach ($jos_advance_orders as $advance_jo)
+        {
+            // get time schedule
+            $date_schedule = $advance_jo->getDateSchedule();
+            $time_schedule = $date_schedule->format('H:i');
+
+            $hour_schedule = $date_schedule->format('H');
+            $minute_schedule = $date_schedule->format('i');
+
+            // check minutes. for now, if not 00, take up current slot and next one
+            // if hour fits in the last slot but minutes is not 00, move to the next available hub
+            // TODO: need to add custom minutes threshold
+            if ($minute_schedule != '00')
+            {
+                switch($hour_schedule) {
+                    case '8':
+                        $hub_rider_slots[0]--;
+                        $hub_rider_slots[1]--;
+                        break;
+                    case '9':
+                        $hub_rider_slots[1]--;
+                        $hub_rider_slots[2]--;
+                        break;
+                    case '10':
+                        $hub_rider_slots[2]--;
+                        $hub_rider_slots[3]--;
+                        break;
+                    case '11':
+                        $hub_rider_slots[3]--;
+                        $hub_rider_slots[4]--;
+                        break;
+                    case '12':
+                        $hub_rider_slots[4]--;
+                        $hub_rider_slots[5]--;
+                        break;
+                    case '13':
+                        $hub_rider_slots[5]--;
+                        $hub_rider_slots[6]--;
+                        break;
+                    case '14':
+                        $hub_rider_slots[6]--;
+                        $hub_rider_slots[7]--;
+                        break;
+                    case '15':
+                        error_log('No slots for the day');
+                        break;
+                    default:
+                        error_log('Does not fit in any time slot. ' . $time_schedule);
+                }
+            }
+            else
+            {
+                switch ($hour_schedule) {
+                    case '8':
+                        $hub_rider_slots[0]--;
+                        break;
+                    case '9':
+                        $hub_rider_slots[1]--;
+                        break;
+                    case '10':
+                        $hub_rider_slots[2]--;
+                        break;
+                    case '11':
+                        $hub_rider_slots[3]--;
+                        break;
+                    case '12':
+                        $hub_rider_slots[4]--;
+                        break;
+                    case '13':
+                        $hub_rider_slots[5]--;
+                        break;
+                    case '14':
+                        $hub_rider_slots[6]--;
+                        break;
+                    case '15':
+                        $hub_rider_slots[7]--;
+                        break;
+                    default:
+                        error_log('Does not fit in any time slot.' . $time_schedule);
+                }
+            }
+
+        }
+
+        // find first free slot
+        foreach ($hub_rider_slots as $index => $rider_slot)
+        {
+            if ($rider_slot > 0)
+            {
+                $flag_found_slot = true;
+
+                $jo_date_schedule = $start_date;
+                switch ($index) {
+                    case '0':
+                        $jo_date_schedule->setTime(8,0);
+                        break;
+                    case '1':
+                        $jo_date_schedule->setTime(9,0);
+                        break;
+                    case '2':
+                        $jo_date_schedule->setTime(10,0);
+                        break;
+                    case '3':
+                        $jo_date_schedule->setTime(11,0);
+                        break;
+                    case '4':
+                        $jo_date_schedule->setTime(12,0);
+                        break;
+                    case '5':
+                        $jo_date_schedule->setTime(13,0);
+                        break;
+                    case '6':
+                        $jo_date_schedule->setTime(14,0);
+                        break;
+                    case '7':
+                        $jo_date_schedule->setTime(15,0);
+                        break;
+                    default:
+                        error_log('Cannot find time slot.');
+                }
+
+                $results = [
+                    'slot_found' => $flag_found_slot,
+                    'date_schedule' => $jo_date_schedule,
+                ];
+
+                break;
+            }
+        }
+        return $results;
+    }
 }
diff --git a/src/Controller/HubController.php b/src/Controller/HubController.php
index d6334c80..5c8adb04 100644
--- a/src/Controller/HubController.php
+++ b/src/Controller/HubController.php
@@ -152,7 +152,8 @@ class HubController extends Controller
             ->setTimeClose($time_close)
             ->setCoordinates($point)
             ->setBranchCode($req->request->get('branch_code', ''))
-            ->setStatusOpen($req->request->get('status_open') ?? false);
+            ->setStatusOpen($req->request->get('status_open') ?? false)
+            ->setRiderSlots($req->request->get('rider_slots', 0));
     }
 
     protected function setQueryFilters($datatable, QueryBuilder $query)
diff --git a/src/Entity/Hub.php b/src/Entity/Hub.php
index f92a424e..9edcb88a 100644
--- a/src/Entity/Hub.php
+++ b/src/Entity/Hub.php
@@ -56,6 +56,12 @@ class Hub
      */
     protected $status_open;
 
+    // number of rider slots per day
+    /**
+     * @ORM\Column(type="integer")
+     */
+    protected $rider_slots;
+
     public function __construct()
     {
         $this->time_open = new DateTime();
@@ -150,4 +156,15 @@ class Hub
         return $this->status_open;
     }
 
+    public function setRiderSlots($rider_slots)
+    {
+        $this->rider_slots = $rider_slots;
+        return $this;
+    }
+
+    public function getRiderSlots()
+    {
+        return $this->rider_slots;
+    }
+
 }
diff --git a/templates/hub/form.html.twig b/templates/hub/form.html.twig
index aed63021..b47b546d 100644
--- a/templates/hub/form.html.twig
+++ b/templates/hub/form.html.twig
@@ -90,7 +90,14 @@
                                         <input type="text" name="branch_code" class="form-control m-input" value="{{ obj.getBranchCode() }}">
                                         <div class="form-control-feedback hide" data-field="branch_code"></div>
                                     </div>
-                                    <div class="col-lg-6">
+                                    <div class="col-lg-3">
+                                        <label for="rider_slots" data-field="rider_slots">
+                                            Number of Riders Per Slot
+                                        </label>
+                                        <input type="text" name="rider_slots" class="form-control m-input" value="{{ obj.getRiderSlots() }}">
+                                        <div class="form-control-feedback hide" data-field="rider_slots"></div>
+                                    </div>
+                                    <div class="col-lg-3">
                                         <span class="m-switch m-switch--icon block-switch">
                                             <label>
                                                 <input type="checkbox" name="status_open" id="status-open" value="1"{{ obj.isStatusOpen ? ' checked' }}>