src/Pure/Tools/build_log.scala

 */
 
 package isabelle
 
 
+import java.util.Locale
 import java.io.{File => JFile}
 import java.time.ZonedDateTime
 import java.time.format.{DateTimeFormatter, DateTimeParseException}
 
 import scala.collection.mutable

 
 
   /* header and meta data */
 
   val Date_Format =
-    Date.Format.make_patterns(List("EEE MMM d HH:mm:ss VV yyyy", "EEE MMM d HH:mm:ss O yyyy"),
+    Date.Format.make_variants(
+      List("EEE MMM d HH:mm:ss VV yyyy", "EEE MMM d HH:mm:ss O yyyy"),
+      List(Locale.ENGLISH, Locale.GERMAN),
       // workaround for jdk-8u102
       s => Word.implode(Word.explode(s).map({
         case "CET" | "MET" => "GMT+1"
         case "CEST" | "MEST" => "GMT+2"
         case "EST" => "GMT+1"  // FIXME ??