Java Calculate Number of Nanoseconds Between two ZonedDateTime

import java.time.ZonedDateTime;
import java.time.temporal.ChronoUnit;

public class NanosecondsBetweenZonedDateTimeExample {
    public static void main(String... args) {
        ZonedDateTime startZonedDateTime = ZonedDateTime.parse("2022-01-01T08:15:30+10:00[Australia/Sydney]");
        ZonedDateTime endZonedDateTime = ZonedDateTime.parse("2022-01-01T08:15:35+10:00[Australia/Sydney]");

        // Calculate Number of Nanoseconds Between two ZonedDateTime
        long numberOfNanoseconds = ChronoUnit.NANOS.between(startZonedDateTime, endZonedDateTime);

        System.out.println(String.format("Number of nanoseconds between %s and %s is %d",
                startZonedDateTime,
                endZonedDateTime,
                numberOfNanoseconds));

    }
}

Number of nanoseconds between 2022-01-01T09:15:30+11:00[Australia/Sydney] and 2022-01-01T09:15:35+11:00[Australia/Sydney] is 5000000000