diff --git a/src/main/java/org/caosdb/datetime/UTCTimeZoneShift.java b/src/main/java/org/caosdb/datetime/UTCTimeZoneShift.java
index 4b3063b82ede350d3e58f8537bb17c00a091b2a3..5cd9de48a183f18dd0ca39adaae0c7671cf8efdb 100644
--- a/src/main/java/org/caosdb/datetime/UTCTimeZoneShift.java
+++ b/src/main/java/org/caosdb/datetime/UTCTimeZoneShift.java
@@ -141,6 +141,7 @@ public class UTCTimeZoneShift extends TimeZone {
   public static String getISO8601Offset(TimeZone timezone, long date) {
     int divisor = 1000 * 60 * 60;
     int offset = timezone.getOffset(date);
+    // convert the ms to the ISO format
     int sign = Integer.signum(offset);
     int h = Integer.divideUnsigned(sign * offset, divisor);
     int m = Integer.remainderUnsigned(sign * offset, divisor);