public static Period instantAsAge(final Instant time, final Instant now) {
        Objects.requireNonNull(time);
        Objects.requireNonNull(now);

        if (time.isBefore(now)) {
            return Period.between(
                    LocalDate.ofInstant(time, ZoneOffset.UTC),
                    LocalDate.ofInstant(now, ZoneOffset.UTC));
        } else {
            return Period.between(
                    LocalDate.ofInstant(now, ZoneOffset.UTC),
                    LocalDate.ofInstant(time, ZoneOffset.UTC));
        }
    }
If time is in the past then return the period from time until now().
If time is in the future then return the period from now() until time.
stroom-util/src/main/java/stroom/util/time/TimeUtils.java