diff --git a/Arduino/klock4/klock4.ino b/Arduino/klock4/klock4.ino
index 9b9bc72..89b44e9 100644
--- a/Arduino/klock4/klock4.ino
+++ b/Arduino/klock4/klock4.ino
@@ -137,10 +137,10 @@ void clockUpdate() {
   ts += UPDATE_INTERVAL_S;
 
   /* drift determined experimentally:
-   * ~3.5 ms "calculation time" per cycle
-   * ~12.6ms/s aka 63.6ms/cycle other drift (wakeup time?)
+   * ~3.5ms/cycle "calculation time"
+   * 60ms/cycle other drift (wakeup time?)
    */
-  #define DRIFT_MS 65
+  #define DRIFT_MS 63
   #define SCHEDULE_DELAY_MS ((1000 * UPDATE_INTERVAL_S) - DRIFT_MS)
   scheduler.scheduleDelayed(clockUpdate, SCHEDULE_DELAY_MS);
 
@@ -173,7 +173,7 @@ void loop() {
       break;
   }
   */
-  ts = 1618048100L;
+  ts = 1618651100L;
 
   scheduler.execute();