diff --git a/notmuch-private.h b/notmuch-private.h
index b67aa905..99fbb4b2 100644
--- a/notmuch-private.h
+++ b/notmuch-private.h
@@ -155,10 +155,8 @@ _notmuch_thread_create (const void *talloc_owner,
 			const char *thread_id);
 
 void
-_notmuch_thread_add_tag (notmuch_thread_t *thread, const char *tag);
-
-void
-_notmuch_thread_set_subject (notmuch_thread_t *thread, const char *subject);
+_notmuch_thread_add_message (notmuch_thread_t *thread,
+			     notmuch_message_t *message);
 
 /* message.cc */
 
diff --git a/notmuch.c b/notmuch.c
index c6807e83..ba5ba831 100644
--- a/notmuch.c
+++ b/notmuch.c
@@ -733,70 +733,6 @@ query_string_from_args (void *ctx, int argc, char *argv[])
     return query_string;
 }
 
-static int
-search_command (int argc, char *argv[])
-{
-    void *local = talloc_new (NULL);
-    notmuch_database_t *notmuch = NULL;
-    notmuch_query_t *query;
-    notmuch_thread_results_t *results;
-    notmuch_thread_t *thread;
-    notmuch_tags_t *tags;
-    char *query_str;
-    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
-
-    notmuch = notmuch_database_open (NULL);
-    if (notmuch == NULL) {
-	ret = 1;
-	goto DONE;
-    }
-
-    query_str = query_string_from_args (local, argc, argv);
-
-    query = notmuch_query_create (notmuch, query_str);
-    if (query == NULL) {
-	fprintf (stderr, "Out of memory\n");
-	ret = 1;
-	goto DONE;
-    }
-
-    for (results = notmuch_query_search_threads (query);
-	 notmuch_thread_results_has_more (results);
-	 notmuch_thread_results_advance (results))
-    {
-	int first = 1;
-
-	thread = notmuch_thread_results_get (results);
-
-	printf ("%s %s",
-		notmuch_thread_get_thread_id (thread),
-		notmuch_thread_get_subject (thread));
-
-	printf (" (");
-	for (tags = notmuch_thread_get_tags (thread);
-	     notmuch_tags_has_more (tags);
-	     notmuch_tags_advance (tags))
-	{
-	    if (! first)
-		printf (" ");
-	    printf ("%s", notmuch_tags_get (tags));
-	    first = 0;
-	}
-	printf (")\n");
-
-	notmuch_thread_destroy (thread);
-    }
-
-    notmuch_query_destroy (query);
-
-  DONE:
-    if (notmuch)
-	notmuch_database_close (notmuch);
-    talloc_free (local);
-
-    return ret;
-}
-
 /* Format a nice representation of 'time' relative to the current time.
  *
  * Examples include:
@@ -868,6 +804,76 @@ _format_relative_date (void *ctx, time_t then)
 #undef HOUR
 #undef DAY
 
+static int
+search_command (int argc, char *argv[])
+{
+    void *local = talloc_new (NULL);
+    notmuch_database_t *notmuch = NULL;
+    notmuch_query_t *query;
+    notmuch_thread_results_t *results;
+    notmuch_thread_t *thread;
+    notmuch_tags_t *tags;
+    char *query_str;
+    const char *relative_date;
+    time_t date;
+    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
+
+    notmuch = notmuch_database_open (NULL);
+    if (notmuch == NULL) {
+	ret = 1;
+	goto DONE;
+    }
+
+    query_str = query_string_from_args (local, argc, argv);
+
+    query = notmuch_query_create (notmuch, query_str);
+    if (query == NULL) {
+	fprintf (stderr, "Out of memory\n");
+	ret = 1;
+	goto DONE;
+    }
+
+    for (results = notmuch_query_search_threads (query);
+	 notmuch_thread_results_has_more (results);
+	 notmuch_thread_results_advance (results))
+    {
+	int first = 1;
+
+	thread = notmuch_thread_results_get (results);
+
+	date = notmuch_thread_get_oldest_date (thread);
+	relative_date = _format_relative_date (local, date);
+
+	printf ("%s (%s) %s",
+		notmuch_thread_get_thread_id (thread),
+		relative_date,
+		notmuch_thread_get_subject (thread));
+
+	printf (" (");
+	for (tags = notmuch_thread_get_tags (thread);
+	     notmuch_tags_has_more (tags);
+	     notmuch_tags_advance (tags))
+	{
+	    if (! first)
+		printf (" ");
+	    printf ("%s", notmuch_tags_get (tags));
+	    first = 0;
+	}
+	printf (")\n");
+
+	notmuch_thread_destroy (thread);
+    }
+
+    notmuch_query_destroy (query);
+
+  DONE:
+    if (notmuch)
+	notmuch_database_close (notmuch);
+    talloc_free (local);
+
+    return ret;
+}
+
 /* Get a nice, single-line summary of message. */
 static const char *
 _get_one_line_summary (void *ctx, notmuch_message_t *message)
diff --git a/notmuch.h b/notmuch.h
index 3f59709a..a3608ba0 100644
--- a/notmuch.h
+++ b/notmuch.h
@@ -488,6 +488,16 @@ notmuch_thread_get_thread_id (notmuch_thread_t *thread);
 const char *
 notmuch_thread_get_subject (notmuch_thread_t *thread);
 
+/* Get the date of the oldest message in 'thread' as a time_t value.
+ */
+time_t
+notmuch_thread_get_oldest_date (notmuch_thread_t *thread);
+
+/* Get the date of the oldest message in 'thread' as a time_t value.
+ */
+time_t
+notmuch_thread_get_newest_date (notmuch_thread_t *thread);
+
 /* Get the tags for 'thread', returning a notmuch_tags_t object which
  * can be used to iterate over all tags.
  *
diff --git a/query.cc b/query.cc
index 170ab752..2fe3965f 100644
--- a/query.cc
+++ b/query.cc
@@ -178,8 +178,6 @@ notmuch_query_search_threads (notmuch_query_t *query)
     const char *thread_id;
     notmuch_message_results_t *message_results;
     notmuch_message_t *message;
-    notmuch_tags_t *tags;
-    const char *tag;
     GHashTable *seen;
 
     thread_results = talloc (query, notmuch_thread_results_t);
@@ -207,27 +205,15 @@ notmuch_query_search_threads (notmuch_query_t *query)
 					    thread_id, NULL,
 					    (void **) &thread))
 	{
-	    const char *subject;
-
 	    thread = _notmuch_thread_create (query, query->notmuch,
 					     thread_id);
 
-	    subject = notmuch_message_get_header (message, "subject");
-
-	    _notmuch_thread_set_subject (thread, subject);
-
 	    g_hash_table_insert (seen, xstrdup (thread_id), thread);
 
 	    g_ptr_array_add (thread_results->threads, thread);
 	}
 
-	for (tags = notmuch_message_get_tags (message);
-	     notmuch_tags_has_more (tags);
-	     notmuch_tags_advance (tags))
-	{
-	    tag = notmuch_tags_get (tags);
-	    _notmuch_thread_add_tag (thread, tag);
-	}
+	_notmuch_thread_add_message (thread, message);
 
 	notmuch_message_destroy (message);
     }
diff --git a/thread.cc b/thread.cc
index e4c9e111..b67dfade 100644
--- a/thread.cc
+++ b/thread.cc
@@ -30,6 +30,10 @@ struct _notmuch_thread {
     char *thread_id;
     char *subject;
     GHashTable *tags;
+
+    notmuch_bool_t has_message;
+    time_t oldest;
+    time_t newest;
 };
 
 static int
@@ -74,6 +78,10 @@ _notmuch_thread_create (const void *talloc_owner,
     thread->tags = g_hash_table_new_full (g_str_hash, g_str_equal,
 					  free, NULL);
 
+    thread->has_message = 0;
+    thread->oldest = 0;
+    thread->newest = 0;
+
     return thread;
 }
 
@@ -84,15 +92,36 @@ notmuch_thread_get_thread_id (notmuch_thread_t *thread)
 }
 
 void
-_notmuch_thread_add_tag (notmuch_thread_t *thread, const char *tag)
+_notmuch_thread_add_message (notmuch_thread_t *thread,
+			     notmuch_message_t *message)
 {
-    g_hash_table_insert (thread->tags, xstrdup (tag), NULL);
-}
+    notmuch_tags_t *tags;
+    const char *tag;
+    time_t date;
 
-void
-_notmuch_thread_set_subject (notmuch_thread_t *thread, const char *subject)
-{
-    thread->subject = talloc_strdup (thread, subject);
+    if (! thread->subject) {
+	const char *subject;
+	subject = notmuch_message_get_header (message, "subject");
+	thread->subject = talloc_strdup (thread, subject);
+    }
+
+    for (tags = notmuch_message_get_tags (message);
+	 notmuch_tags_has_more (tags);
+	 notmuch_tags_advance (tags))
+    {
+	tag = notmuch_tags_get (tags);
+	g_hash_table_insert (thread->tags, xstrdup (tag), NULL);
+    }
+
+    date = notmuch_message_get_date (message);
+
+    if (date < thread->oldest || ! thread->has_message)
+	thread->oldest = date;
+
+    if (date > thread->newest || ! thread->has_message)
+	thread->newest = date;
+
+    thread->has_message = 1;
 }
 
 const char *
@@ -101,6 +130,18 @@ notmuch_thread_get_subject (notmuch_thread_t *thread)
     return thread->subject;
 }
 
+time_t
+notmuch_thread_get_oldest_date (notmuch_thread_t *thread)
+{
+    return thread->oldest;
+}
+
+time_t
+notmuch_thread_get_newest_date (notmuch_thread_t *thread)
+{
+    return thread->newest;
+}
+
 notmuch_tags_t *
 notmuch_thread_get_tags (notmuch_thread_t *thread)
 {