TimerScheduledFuture correctly calculates getDelay result

Issue: SPR-13977

spring-context-support/src/main/java/org/springframework/scheduling/commonj/TimerManagerTaskScheduler.java

 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -134,7 +134,7 @@ public class TimerManagerTaskScheduler extends TimerManagerAccessor implements T
 
 		@Override
 		public long getDelay(TimeUnit unit) {
-			return unit.convert(System.currentTimeMillis() - this.timer.getScheduledExecutionTime(), TimeUnit.MILLISECONDS);
+			return unit.convert(this.timer.getScheduledExecutionTime() - System.currentTimeMillis(), TimeUnit.MILLISECONDS);
 		}
 
 		@Override