diff -r fd73e0019605 -r ea528dc9962d src/Pure/General/time.scala
--- a/src/Pure/General/time.scala	Wed Oct 05 20:06:54 2016 +0200
+++ b/src/Pure/General/time.scala	Wed Oct 05 20:13:32 2016 +0200
@@ -27,7 +27,7 @@
   def print_seconds(s: Double): String =
     String.format(Locale.ROOT, "%.3f", s.asInstanceOf[AnyRef])
 
-  def instant(t: Instant): Time = ms(t.getEpochSecond + t.getNano / 1000000L)
+  def instant(t: Instant): Time = ms(t.getEpochSecond * 1000L + t.getNano / 1000000L)
 }
 
 final class Time private(val ms: Long) extends AnyVal