diff --git a/tools/jslint/check-all.js b/tools/jslint/check-all.js
index e8796cc1ca..f6bccf8d8f 100644
--- a/tools/jslint/check-all.js
+++ b/tools/jslint/check-all.js
@@ -3,7 +3,7 @@
 // Global variables, categorized by place of definition.
 var globals =
     // Third-party libraries
-      ' $ jQuery Spinner Handlebars'
+      ' $ jQuery Spinner Handlebars XDate'
 
     // index.html
     + ' initial_pointer email class_list people_list have_initial_messages'
diff --git a/zephyr/jstemplates/zephyr.html b/zephyr/jstemplates/zephyr.html
index f5799c801d..661ce20432 100644
--- a/zephyr/jstemplates/zephyr.html
+++ b/zephyr/jstemplates/zephyr.html
@@ -54,7 +54,7 @@
             <span class="zephyr_sender_email invisible">{{sender_email}}</span>
         </span>
     {{/include_sender}}
-        <span class="zephyr_time" title="{{full_date_str}}">{{timestr}}</span>
+        <span class="zephyr_time" title="{{full_date_str}}">{{{timestr}}}</span>
         <div class="zephyr_content">{{{content}}}</div>
     </td>
 </tr>
diff --git a/zephyr/static/js/zephyr.js b/zephyr/static/js/zephyr.js
index 10feee1ea1..74fe9ba314 100644
--- a/zephyr/static/js/zephyr.js
+++ b/zephyr/static/js/zephyr.js
@@ -229,6 +229,27 @@ function clear_table(table_name) {
     message_groups[table_name] = [];
 }
 
+function add_display_time(zephyr, prev) {
+    var two_digits = function (x) { return ('0' + x).slice(-2); };
+    var time = new XDate(zephyr.timestamp * 1000);
+    var include_date = zephyr.include_recipient;
+
+    if (prev !== undefined) {
+        var prev_time = new XDate(prev.timestamp * 1000);
+        if (time.toDateString() !== prev_time.toDateString()) {
+            include_date = true;
+        }
+    }
+
+    if (include_date) {
+        zephyr.timestr = time.toString("MMM dd") + "&nbsp;&nbsp;" +
+            time.toString("HH:mm");
+    } else {
+        zephyr.timestr = time.toString("HH:mm");
+    }
+    zephyr.full_date_str = time.toLocaleString();
+}
+
 function add_to_table(zephyrs, table_name, filter_function, where) {
     if (zephyrs.length === 0)
         return;
@@ -291,6 +312,8 @@ function add_to_table(zephyrs, table_name, filter_function, where) {
             ids_where_next_is_same_sender.push(prev.id);
         }
 
+        add_display_time(zephyr, prev);
+
         zephyr.dom_id = table_name + zephyr.id;
 
         zephyrs_to_render.push(zephyr);
@@ -381,12 +404,6 @@ function add_zephyr_metadata(dummy, zephyr) {
         break;
     }
 
-    var time = new Date(zephyr.timestamp * 1000);
-    var two_digits = function (x) { return ('0' + x).slice(-2); };
-    zephyr.timestr = two_digits(time.getHours())
-                   + ':' + two_digits(time.getMinutes());
-    zephyr.full_date_str = time.toLocaleString();
-
     zephyr_dict[zephyr.id] = zephyr;
 }