Function human-readable-duration now outputs only two significant parts by default.

[svetlyak40wt]

This can be configurable by second optional argument.

LTD> (human-readable-duration (duration :week 42 :day 0 :hour 2 :minute 3 :sec 15 :nsec 214354))
"42 weeks 2 hours"

instead of:

LTD> (human-readable-duration (duration :week 42 :day 0 :hour 2 :minute 3 :sec 15 :nsec 214354))
"42 weeks 2 hours 3 minutes 15 seconds 214354 nsecs"

Using second optional argument, you can set a number of parts to output:

LTD> (human-readable-duration (duration :week 42 :day 0 :hour 2 :minute 3 :sec 15 :nsec 214354)
                              nil
                              4)
"42 weeks 2 hours 3 minutes 15 seconds"

Using third optional argument, you can add support for another language
with proper pluralization:

LTD> (defun russian-format-part (stream part-type value)
       (format stream
               "~A ~A"
               value
               (ecase part-type
                 (:weeks (cl-inflector:pluralize value "неделя" "недель"))
                 (:days (cl-inflector:pluralize value "день" "дней"))
                 (:hours (cl-inflector:pluralize value "час" "часов"))
                 (:minutes (cl-inflector:pluralize value "минута" "минут"))
                 (:secs (cl-inflector:pluralize value "секунда" "секунд"))
                 (:nsecs (cl-inflector:pluralize value "наносекунда" "наносекунд")))))
RUSSIAN-FORMAT-PART
LTD> (human-readable-duration (duration :week 42 :day 0 :hour 2 :minute 3 :sec 15 :nsec 214354)
                              nil
                              4
                              'russian-format-part)
"42 недель 2 часов 3 минут 15 секунд"