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/chat_box.js b/oh_queue/static/js/components/chat_box.js
index f223c86..da572bf 100644
--- a/oh_queue/static/js/components/chat_box.js
+++ b/oh_queue/static/js/components/chat_box.js
@@ -23,14 +23,16 @@ function ChatBox({ currentUser, socket, id, mode }) {
         if (!typed.trim()) {
             return;
         }
+        // Time is initialized in "send_chat_message".
         app.makeRequest("send_chat_message", {
             content: typed,
             mode,
             id,
+            time: 0
         });
         setTyped("");
     };
-
+    
     const scrollDown = () => {
         $('[data-toggle="tooltip"]').tooltip()
         historyRef.current.scrollTop = historyRef.current.scrollHeight;
@@ -43,30 +45,64 @@ function ChatBox({ currentUser, socket, id, mode }) {
             if (message.mode !== mode || message.id !== id) {
                 return;
             }
-            setMessages(messages.concat([[message.sender, message.content]]));
+            setMessages(messages.concat([[
+                message.sender,
+                message.content,
+                message.time
+            ]]));
         });
         return () => socket.removeAllListeners("chat_message");
     }, [messages]);
 
-    const body = messages.map(([sender, message], i) => {
+    const body = messages.map(([sender, message, time], i) => {
+        function formatTitle(name, time) {
+            if (name === undefined) { 
+                return time
+            } else if (time === undefined) {
+                return name
+            }
+            return name + ' | ' + time;
+        }
+        
         if (sender.id === currentUser.id) {
             return (
                 <div className="my-chat-bubble">
-                    <div className="chat-text">{message}</div>
+                    <div
+                        className="chat-text"
+                        data-toggle="tooltip"
+                        data-placement="right"
+                        title={formatTitle(time)}
+                    >
+                        {message}
+                    </div>
                 </div>
             )
         } else if (messages[i + 1] && sender.id === messages[i + 1][0].id) {
             return (
                 <div className="chat-bubble">
                     <div className="chat-icon none">{sender.shortName[0]}</div>
-                    <div className="chat-text" data-toggle="tooltip" data-placement="right" title={sender.name}>{message}</div>
+                    <div 
+                        className="chat-text"
+                        data-toggle="tooltip"
+                        data-placement="right"
+                        title={formatTitle(sender.name, time)}
+                    >
+                        {message}
+                    </div>
                 </div>
             )
         } else {
             return (
                 <div className="chat-bubble">
                     <div className="chat-icon">{sender.shortName[0]}</div>
-                    <div className="chat-text" data-toggle="tooltip" data-placement="right" title={sender.name}>{message}</div>
+                    <div 
+                        className="chat-text"
+                        data-toggle="tooltip"
+                        data-placement="right"
+                        title={formatTitle(sender.name, time)}
+                    >
+                        {message}
+                    </div>
                 </div>
             )
         }
diff --git a/oh_queue/views.py b/oh_queue/views.py
index 4dc92e7..4fa577c 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"],
@@ -1140,6 +1155,8 @@ def send_chat_message(data):
     event_id = data["id"]
 
     data["sender"] = user_json(current_user)
+    message_time = get_current_time().strftime("%a %-I:%M%p")
+    data["time"] = message_time
 
     if mode == "appointment":
         appointment = Appointment.query.filter_by(course=get_course(), id=event_id).one()