public static String instantAsAgeStr(final Instant time, final Instant now) {
        Objects.requireNonNull(time);
        Objects.requireNonNull(now);

        return time.isBefore(now)
                ? toPeriodOrDurationStr(time, now)
                : toPeriodOrDurationStr(now, time);
    }
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