Index: trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java	(revision 17113)
+++ trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java	(revision 17114)
@@ -68,9 +68,11 @@
     public static long tsFromString(String str) {
         // "2007-07-25T09:26:24{Z|{+|-}01[:00]}"
-        if (checkLayout(str, "xxxx-xx-xx")) {
+        if (checkLayout(str, "xxxx-xx-xx") ||
+                checkLayout(str, "xxxx-xx") ||
+                checkLayout(str, "xxxx")) {
             final ZonedDateTime local = ZonedDateTime.of(
                     parsePart4(str, 0),
-                    parsePart2(str, 5),
-                    parsePart2(str, 8),
+                    str.length() > 5 ? parsePart2(str, 5) : 1,
+                    str.length() > 8 ? parsePart2(str, 8) : 1,
                     0, 0, 0, 0, ZoneOffset.UTC);
             return local.toInstant().toEpochMilli();
@@ -129,5 +131,5 @@
         try {
             // slow path for fractional seconds different from millisecond precision
-            return Instant.parse(str).toEpochMilli();
+            return ZonedDateTime.parse(str).toInstant().toEpochMilli();
         } catch (IllegalArgumentException | DateTimeParseException ex) {
             throw new UncheckedParseException("The date string (" + str + ") could not be parsed.", ex);