+/* 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);
+