Index: /trunk/src/org/openstreetmap/josm/io/AbstractReader.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/io/AbstractReader.java	(revision 17753)
+++ /trunk/src/org/openstreetmap/josm/io/AbstractReader.java	(revision 17754)
@@ -431,5 +431,5 @@
         }
         try {
-            int timestamp = timestampCache.computeIfAbsent(time, t -> (int) (DateUtils.parseInstant(t).getEpochSecond()));
+            int timestamp = timestampCache.computeIfAbsent(time, t -> (int) DateUtils.parseInstant(t).getEpochSecond());
             current.setRawTimestamp(timestamp);
         } catch (UncheckedParseException | DateTimeException e) {