What is the Maximum value for Java Duration

It looks like Duration is stored in seconds (up to Long.MAX_VALUE) and nanoseconds (up to 999,999,999). Then the biggest duration possible is:

Duration d = Duration.ofSeconds(Long.MAX_VALUE, 999_999_999);

When I print it (System.out.print(d)) I get the following:

PT2562047788015215H30M7.999999999S

which means: 2562047788015215 hours, 30 minutes, and 7.999999999 seconds.

Simple:

Duration maxDur = ChronoUnit.FOREVER.getDuration();