diff --git a/oh_queue/static/css/style.css b/oh_queue/static/css/style.css
index cbe5276..14d725c 100644
--- a/oh_queue/static/css/style.css
+++ b/oh_queue/static/css/style.css
@@ -749,6 +749,18 @@ h1.truncate, h2.truncate, h3.truncate, h4.truncate, h5.truncate, h6.truncate {
     border-color: orange;
 }
 
+.panel-warning-short > .panel-heading {
+  color: #fff;
+  background: repeating-linear-gradient(
+    45deg,
+    orange,
+    orange 10px,
+    #EE9E00 10px,
+    #EE9E00 20px
+  );
+  border-color: #EE9E00;
+}
+
 .panel-success {
     border-color: #4cae4c;
 }
@@ -759,6 +771,41 @@ h1.truncate, h2.truncate, h3.truncate, h4.truncate, h5.truncate, h6.truncate {
     border-color: #4cae4c;
 }
 
+.panel-success-short > .panel-heading {
+    color: #fff;
+    background: repeating-linear-gradient(
+      45deg,
+      #5cb85c,
+      #5cb85c 10px,
+      #4cae4c 10px,
+      #4cae4c 20px
+    );
+    border-color: #4cae4c;
+}
+
+.panel-primary-short > .panel-heading {
+    color: #fff;
+    background: repeating-linear-gradient(
+      45deg,
+      #337ab7,
+      #337ab7 10px,
+      #3C8CD1 10px,
+      #3C8CD1 20px
+    );
+    border-color: #337ab7;
+}
+
+.panel-danger-short > .panel-heading {
+  color: #ac4b49;
+  background: repeating-linear-gradient(
+    45deg,
+    #f2dede,
+    #f2dede 10px,
+    #F5D0D0 10px,
+    #F5D0D0 20px
+  );
+  border-color: #F5D0D0;
+}
 
 .btn-take-over {
     position: absolute;
@@ -839,6 +886,21 @@ h4.list-group-item-heading::before {
     border-top: 1px solid #ddd;;
 }
 
+.panel.panel-default-short > .panel-heading{
+    border-top: 1px solid #ddd;
+    background: repeating-linear-gradient(
+      45deg,
+      #ddd,
+      #ddd 10px,
+      #D0D0D0 10px,
+      #D0D0D0 20px
+    );
+}
+
+.panel.panel-default {
+    border-top: 1px solid #ddd;;
+}
+
 .tooltip+.btn-block {
     margin-top: 5px;
 }
diff --git a/oh_queue/static/js/components/admin_appointments_manager.js b/oh_queue/static/js/components/admin_appointments_manager.js
index cd3001f..382cc3b 100644
--- a/oh_queue/static/js/components/admin_appointments_manager.js
+++ b/oh_queue/static/js/components/admin_appointments_manager.js
@@ -61,8 +61,11 @@ function AdminAppointmentsManager({ state }) {
                 <tr>
                     <td>
                         <p>
-                            How many appointments should a student have be pending simultaneously?
+                        How many appointments should a student have be pending simultaneously?
                         </p>
+                            (by 
+                            <ConfigLinkedToggle config={state.config} configKey="appointment_or_minutes" onText="minutes" offText="number"/> 
+                            )
                     </td>
                     <td className="col-md-3">
                         <ConfigLinkedNumeric
diff --git a/oh_queue/static/js/components/appointment_card.js b/oh_queue/static/js/components/appointment_card.js
index 46448b2..802c16c 100644
--- a/oh_queue/static/js/components/appointment_card.js
+++ b/oh_queue/static/js/components/appointment_card.js
@@ -3,23 +3,41 @@ const calcSpareCapacity = appointment => Math.max(0, appointment.capacity - appo
 function AppointmentCard({ currentUser, locations, appointment, assignments, compact, onStudentSignup }) {
     let panelColor = "panel-default";
     let canAdd = true;
+    let shortDuration = 600;
 
     const spareCapacity = calcSpareCapacity(appointment);
 
     if (currentUser.isStaff) {
         if (appointment.helper && appointment.status === "hidden") {
             panelColor = "panel-danger";
+            if (appointment.duration <= shortDuration) {
+                panelColor = "panel-danger-short";
+            }
         } else if (appointment.helper && appointment.helper.id === currentUser.id) {
             panelColor = "panel-primary";
+            if (appointment.duration <= shortDuration) {
+                panelColor = "panel-primary-short";
+            }
         } else if (currentUser.isStaff && !appointment.helper) {
             panelColor = "panel-warning";
+            if (appointment.duration <= shortDuration) {
+                panelColor = "panel-warning-short";
+            }
         }
     } else {
         if (appointment.signups.some(({ user }) => user && user.id === currentUser.id)) {
             panelColor = "panel-success";
             canAdd = false;
+            if (appointment.duration <= shortDuration) {
+                panelColor = "panel-success-short";
+            }
         } else if (spareCapacity === 0) {
             panelColor = "panel-danger";
+            if (appointment.duration <= shortDuration) {
+                panelColor = "panel-danger-short";
+            }
+        } else if (appointment.duration <= shortDuration) {
+            panelColor = "panel-default-short";
         }
     }
 
diff --git a/oh_queue/views.py b/oh_queue/views.py
index 4dc92e7..0701526 100644
--- a/oh_queue/views.py
+++ b/oh_queue/views.py
@@ -319,6 +319,12 @@ def init_config():
         public=True,
         course=get_course(),
     ))
+    db.session.add(ConfigEntry(
+        key='appointment_or_minutes',
+        value='false',
+        public=True,
+        course=get_course(),
+    ))
     db.session.add(ConfigEntry(
         key='show_okpy_backups',
         value='false',
@@ -922,6 +928,7 @@ def assign_appointment(data):
         daily_threshold = int(ConfigEntry.query.filter_by(key="daily_appointment_limit", course=get_course()).one().value)
         weekly_threshold = int(ConfigEntry.query.filter_by(key="weekly_appointment_limit", course=get_course()).one().value)
         pending_threshold = int(ConfigEntry.query.filter_by(key="simul_appointment_limit", course=get_course()).one().value)
+        pending_metric= ConfigEntry.query.filter_by(key="appointment_or_minutes", course=get_course()).one().value
 
         start = appointment.start_time.replace(hour=0, minute=0, second=0, microsecond=0)
         week_start = start - datetime.timedelta(days=appointment.start_time.weekday())
@@ -940,13 +947,21 @@ def assign_appointment(data):
         ).count()
         if num_today >= daily_threshold:
             return socket_error("You have already signed up for {} OH slots for the same day".format(daily_threshold))
-
         num_pending = AppointmentSignup.query.join(AppointmentSignup.appointment).filter(
             Appointment.status == AppointmentStatus.pending,
             AppointmentSignup.user_id == current_user.id,
-        ).count()
-        if num_pending >= pending_threshold:
-            return socket_error("You have already signed up for {} OH slots that have not yet occurred.".format(pending_threshold))
+        )
+        if pending_metric != 'false':
+            start = appointment.duration
+            num_pend = [appt.appointment.duration for appt in list(num_pending)]
+            threshold  = datetime.timedelta(minutes=pending_threshold)
+            for item in num_pend:
+                start += item
+            if start > threshold:
+                return socket_error("You cannot sign up for more than {} minutes of OH that have not yet occurred.".format(pending_threshold))
+        else:
+            if num_pending.count() >= pending_threshold:
+                return socket_error("You have already signed up for {} OH slots that have not yet occurred.".format(pending_threshold))
 
     old_signup = AppointmentSignup.query.filter_by(
         appointment_id=data["appointment_id"],