--- trunk/panel-plugin/datetime.c	2008-06-08 19:17:04.000000000 -0700
+++ exp2/panel-plugin/datetime.c	2008-06-10 03:20:41.000000000 -0700
@@ -1,4 +1,4 @@
-/*  $Id$
+/*  $Id: datetime.c,v 1.3 2008/06/10 10:08:58 stephent Exp stephent $
  *
  *  Copyright (C) 2003 Choe Hwanjin(krisna@kldp.org)
  *  Copyright (c) 2006 Remco den Breeje <remco@sx.mine.nu>
@@ -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)
@@ -143,15 +157,8 @@
     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;
+  /* 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;
@@ -185,6 +192,7 @@
   struct tm *current;
   gchar *utf8str;
   gchar *format = NULL;
+  guint wake_interval;  /* milliseconds to next update */
 
   switch(datetime->layout)
   {
@@ -211,11 +219,9 @@
   /* 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,
+    /* Compute the time to the next update and start the timer. */
+    wake_interval = datetime_wake_interval_from_current_time(timeval, datetime->update_interval);
+    datetime->tooltip_timeout_id = g_timeout_add(wake_interval,
       (GSourceFunc) datetime_tooltip_timer, datetime);
   }