diff -u trunk/panel-plugin/datetime.c exp2/panel-plugin/datetime.c
--- trunk/panel-plugin/datetime.c	2008-06-08 19:17:04.000000000 -0700
+++ exp2/panel-plugin/datetime.c	2008-06-10 13:11:03.000000000 -0700
@@ -51,6 +51,20 @@
 }
 
 /*
+ * Compute the wake interval,
+ * which is the time remaining from the current time
+ * to the next larger integral multiple of the update interval.
+ * Setting a timer to this value schedules the next update
+ * to occur on the next second or minute
+ * when the given update interval is 1000 or 60000 milliseconds, respectively.
+ */
+static inline guint datetime_wake_interval_from_current_time(const GTimeVal current_time,
+                                                             const guint update_interval_ms)
+{
+  return (update_interval_ms - datetime_gtimeval_to_ms(current_time) % update_interval_ms);
+}
+
+/*
  * Get date/time string
  */
 gchar * datetime_do_utf8strftime(const char *format, const struct tm *tm)
@@ -143,46 +157,28 @@
     g_free(utf8str);
   }
 
-  /*
-   * Compute the time to the next update and start the timer.
-   * The wake interval is the time remaining
-   * to the next larger integral multiple of the update interval.
-   * Setting the timer to this value schedules the next update
-   * to occur on the next second or minute
-   * when the update interval is 1 or 60 seconds, respectively.
-   */
-  wake_interval = datetime->update_interval - datetime_gtimeval_to_ms(timeval) % datetime->update_interval;
+#if USE_GTK_TOOLTIP_API
+  if (datetime->tooltip_handler_id != 0)
+  {
+    datetime->current_time = current; /* pass current time to tooltip handler */
+    gtk_widget_trigger_tooltip_query(GTK_WIDGET(datetime->button));
+  }
+#endif
+
+  /* Compute the time to the next update and start the timer. */
+  wake_interval = datetime_wake_interval_from_current_time(timeval, datetime->update_interval);
   datetime->timeout_id = g_timeout_add(wake_interval, (GSourceFunc) datetime_update, datetime);
 
   return TRUE;
 }
 
 #if USE_GTK_TOOLTIP_API
-static gboolean datetime_tooltip_timer(t_datetime *datetime)
-{
-
-  /* flag to datetime_query_tooltip that there is no longer an active timeout */
-  datetime->tooltip_timeout_id = 0;
-
-  /*
-   * Run datetime_query_tooltip if the mouse is still there.
-   * If it is run, it'll register *this* function to be called after another
-   * timeout. If not, *this* function won't run again.
-   */
-  gtk_widget_trigger_tooltip_query(GTK_WIDGET(datetime->button));
-
-  /* we don't want to automatically run again */
-  return FALSE;
-}
-
 static gboolean datetime_query_tooltip(GtkWidget *widget,
                                        gint x, gint y,
                                        gboolean keyboard_mode,
                                        GtkTooltip *tooltip,
                                        t_datetime *datetime)
 {
-  GTimeVal timeval;
-  struct tm *current;
   gchar *utf8str;
   gchar *format = NULL;
 
@@ -201,24 +197,10 @@
   if (format == NULL)
     return FALSE;
 
-  g_get_current_time(&timeval);
-  current = localtime((time_t *)&timeval.tv_sec);
-
-  utf8str = datetime_do_utf8strftime(format, current);
+  utf8str = datetime_do_utf8strftime(format, datetime->current_time);
   gtk_tooltip_set_text(tooltip, utf8str);
   g_free(utf8str);
 
-  /* if there is no active timeout to update the tooltip, register one */
-  if (!datetime->tooltip_timeout_id)
-  {
-    /*
-     * I think we can afford to inefficiently poll every
-     * second while the user keeps the mouse here.
-     */
-    datetime->tooltip_timeout_id = g_timeout_add(1000,
-      (GSourceFunc) datetime_tooltip_timer, datetime);
-  }
-
   return TRUE;
 }
 #endif
@@ -694,7 +676,6 @@
 {
   /* stop timeouts */
   g_source_remove(datetime->timeout_id);
-  g_source_remove(datetime->tooltip_timeout_id);
 
   /* destroy widget */
   gtk_widget_destroy(datetime->button);
diff -u trunk/panel-plugin/datetime.h exp2/panel-plugin/datetime.h
--- trunk/panel-plugin/datetime.h	2008-06-08 19:17:04.000000000 -0700
+++ exp2/panel-plugin/datetime.h	2008-06-10 13:27:16.000000000 -0700
@@ -49,8 +49,8 @@
   guint update_interval;  /* time between updates in milliseconds */
   guint timeout_id;
 #if USE_GTK_TOOLTIP_API
-  guint tooltip_timeout_id;
-  gulong tooltip_handler_id;
+  gulong    tooltip_handler_id;
+  struct tm *current_time;
 #endif
 
   /* settings */