Index: /trunk/src/org/openstreetmap/josm/io/nmea/NmeaReader.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/io/nmea/NmeaReader.java	(revision 12434)
+++ /trunk/src/org/openstreetmap/josm/io/nmea/NmeaReader.java	(revision 12435)
@@ -13,4 +13,5 @@
 import java.util.Collections;
 import java.util.Date;
+import java.util.Locale;
 import java.util.Optional;
 
@@ -131,6 +132,6 @@
     public GpxData data;
 
-    private final SimpleDateFormat rmcTimeFmt = new SimpleDateFormat("ddMMyyHHmmss.SSS");
-    private final SimpleDateFormat rmcTimeFmtStd = new SimpleDateFormat("ddMMyyHHmmss");
+    private final SimpleDateFormat rmcTimeFmt = new SimpleDateFormat("ddMMyyHHmmss.SSS", Locale.ENGLISH);
+    private final SimpleDateFormat rmcTimeFmtStd = new SimpleDateFormat("ddMMyyHHmmss", Locale.ENGLISH);
 
     private Date readTime(String p) {