Convert seconds to a stop watch

cli_clock.clj

(defn strftime [secs]
  (format "%02d:%02d:%02d"
          (mod (int (/ secs 3600)) 24)
          (mod (int (/ secs 60)) 60)
          (mod secs 60)))

(defn secs-elapsed-since-midnight []
  (let [now (java.time.ZonedDateTime/now)
        midnight (.truncatedTo now java.time.temporal.ChronoUnit/DAYS)
        duration (java.time.Duration/between midnight now)]
    (.getSeconds duration)))

(defn print-clock
  []
  (let [t (atom (secs-elapsed-since-midnight))]
    (while true
     (do
       (print (strftime @t))
       (flush)
       (Thread/sleep 1000)
       (print "\b\b\b\b\b\b\b\b")
       (flush)
       (swap! t inc)))))

(print-clock)

time_to_str.clj

(defn strftime [secs]
  (format "%02d:%02d:%02d"
          (mod (int (/ secs 3600)) 24)
          (mod (int (/ secs 60)) 60)
          (mod secs 60)))