diff --git a/src/org/hwo/ui/diagram/TimePlotLabeler.java b/src/org/hwo/ui/diagram/TimePlotLabeler.java
index 65de123..08c7398 100644
--- a/src/org/hwo/ui/diagram/TimePlotLabeler.java
+++ b/src/org/hwo/ui/diagram/TimePlotLabeler.java
@@ -43,10 +43,10 @@ public class TimePlotLabeler implements PlotLabeler{
 		second = (int)(pos * 1) % 60;
 		millisecond = (int)(pos * 1000) % 1000;
 		String sh, sm, ss, sms;
-		sh = hour < 10? String.format("0%d", hour) : String.format("%d", hour);
-		sm = minute < 10? String.format("0%d", minute) : String.format("%d", minute);
-		ss = second < 10? String.format("0%d", second) : String.format("%d", second);
-		sms = millisecond < 10? String.format("00%d", millisecond) : millisecond < 100? String.format("0%d", millisecond) : String.format("%d", millisecond);
+		sh = String.format("%02d", hour);
+		sm = String.format("%02d", minute);
+		ss = String.format("%02d", second);
+		sms = String.format("%03d", millisecond);
 		return sh + ":" + sm + ":" + ss + "." + sms;
 	}