diff --git a/cpu/avr/dev/clock.c b/cpu/avr/dev/clock.c
index b71c8660e..94fbc1863 100644
--- a/cpu/avr/dev/clock.c
+++ b/cpu/avr/dev/clock.c
@@ -6,9 +6,27 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 
+/*
+  CLOCK_SECOND is the number of ticks per second.
+  It is defined through CONF_CLOCK_SECOND in the contiki-conf.h for each platform.
+  The usual AVR defaults are 128 or 125 ticks per second, counting a prescaled CPU clock
+  using the 8 bit timer0.
+  
+  As clock_time_t is an unsigned 16 bit data type, intervals up to 512 or 524 seconds
+  can be measured with ~8 millisecond precision. 
+  For longer intervals a 32 bit global is incremented every second. 
+ 
+  clock-avr.h contains the specific setup code for each mcu.
+
+*/
+
+/* count is a 16 bit tick counter that wraps every ~10 minutes, returned by clock_time() */
 static volatile clock_time_t count;
+/* scount is the 8 bit counter that counts ticks modulo CLOCK_SECONDS */
 static volatile uint8_t scount;
+/* seconds is the number of seconds since startup, returned by clock_seconds() */
 volatile unsigned long seconds;
+/* sleepseconds is the number of seconds sleeping since startup, available globally */
 long sleepseconds;
 
 /* Set RADIOSTATS to monitor radio on time (must also be set in the radio driver) */
@@ -32,19 +50,7 @@ extern volatile uint8_t rf230_calibrate;
 static uint8_t calibrate_interval;
 #endif
 
-/*
-  CLOCK_SECOND is the number of ticks per second.
-  It is defined through CONF_CLOCK_SECOND in the contiki-conf.h for each platform.
-  The usual AVR default is ~125 ticks per second, counting a prescaler the CPU clock
-  using the 8 bit timer0.
-  
-  As clock_time_t is an unsigned 16 bit data type, intervals up to 524 seconds
-  can be measured with 8 millisecond precision. 
-  For longer intervals a 32 bit global is incremented every second. 
- 
-  clock-avr.h contains the specific setup code for each mcu.
-
-*/
+#if 0
 /*---------------------------------------------------------------------------*/
 /* This routine can be called to add seconds to the clock after a sleep
  * of an integral number of seconds.
@@ -52,10 +58,28 @@ static uint8_t calibrate_interval;
 void clock_adjust_seconds(uint8_t howmany) {
    seconds += howmany;
    sleepseconds +=howmany;
+   count += howmany * CLOCK_SECOND;
 #if RADIOSTATS
   if (RF230_receive_on) radioontime += howmany;
 #endif
 }
+#endif
+
+/*---------------------------------------------------------------------------*/
+/* This routine can be called to add ticks to the clock after a sleep.
+ */
+void clock_adjust_ticks(uint16_t howmany) {
+   count  += howmany;
+   scount += howmany;
+   while(scount >= CLOCK_SECOND) {
+      scount -= CLOCK_SECOND;
+      seconds++;
+      sleepseconds++;
+#if RADIOSTATS
+      if (RF230_receive_on) radioontime += 1;
+#endif
+   }
+}
 /*---------------------------------------------------------------------------*/
 //SIGNAL(SIG_OUTPUT_COMPARE0)
 ISR(AVR_OUTPUT_COMPARE_INT)
@@ -123,6 +147,7 @@ clock_time(void)
   } while(tmp != count);
   return tmp;
 }
+#if 0
 /*---------------------------------------------------------------------------*/
 /**
  * Delay the CPU for a multiple of TODO
@@ -139,7 +164,7 @@ clock_delay(unsigned int i)
 
 /*---------------------------------------------------------------------------*/
 /**
- * Wait for a multiple of 1 / 125 sec = 0.008 ms.
+ * Wait for a number of clock ticks.
  *
  */
 void
@@ -154,8 +179,9 @@ clock_wait(int i)
 void
 clock_set_seconds(unsigned long sec)
 {
-    // TODO
+    seconds = sec;
 }
+#endif
 
 unsigned long
 clock_seconds(void)
@@ -253,4 +279,4 @@ ISR( _VECTOR(76)) {while (1) x++;}
 ISR( _VECTOR(77)) {while (1) x++;}
 ISR( _VECTOR(78)) {while (1) x++;}
 ISR( _VECTOR(79)) {while (1) x++;}
-#endif
+#endif
\ No newline at end of file
diff --git a/platform/avr-atmega128rfa1/apps/raven-lcd-interface/raven-lcd.c b/platform/avr-atmega128rfa1/apps/raven-lcd-interface/raven-lcd.c
index 0ce1e9c6a..9fd7d7784 100644
--- a/platform/avr-atmega128rfa1/apps/raven-lcd-interface/raven-lcd.c
+++ b/platform/avr-atmega128rfa1/apps/raven-lcd-interface/raven-lcd.c
@@ -224,8 +224,8 @@ void micro_sleep(uint8_t howlong)
        sleep_mode();                            // Sleep
 
        /* Adjust clock.c for the time spent sleeping */
-       extern void clock_adjust_seconds(uint8_t howmany);
-       clock_adjust_seconds(howlong);
+       extern void clock_adjust_ticks(uint16_t howmany);
+       clock_adjust_ticks(howlong * CLOCK_SECOND);
 
 //     if (TIMSK2&(1<<OCIE2A)) break;           // Exit sleep if not awakened by TIMER2
        PRINTF(".");
diff --git a/platform/avr-raven/apps/raven-lcd-interface/raven-lcd.c b/platform/avr-raven/apps/raven-lcd-interface/raven-lcd.c
index 635ed9a73..d2624760a 100644
--- a/platform/avr-raven/apps/raven-lcd-interface/raven-lcd.c
+++ b/platform/avr-raven/apps/raven-lcd-interface/raven-lcd.c
@@ -215,8 +215,8 @@ void micro_sleep(uint8_t howlong)
        sleep_mode();                            // Sleep
 
        /* Adjust clock.c for the time spent sleeping */
-       extern void clock_adjust_seconds(uint8_t howmany);
-       clock_adjust_seconds(howlong);
+       extern void clock_adjust_ticks(uint16_t howmany);
+       clock_adjust_ticks(howlong * CLOCK_SECOND);
 
 //     if (TIMSK2&(1<<OCIE2A)) break;           // Exit sleep if not awakened by TIMER2
        PRINTF(".");