relative date partitioning in clojure.clj

(def dates  [[14 4] [12 4] [15 3] [13 3] [10 3] [1 1]])

(defn get-num-date [[day month]]
  (+ month (* 0.1 day)))

(defn part-dates 
  ([coll]
   (let [curdate (apply max-key get-num-date coll)]
     (part-dates coll curdate)))
  ([coll [day month]]
   (let [mindate (get-num-date (vector day (dec month)))
         fcoll (group-by #(>= (get-num-date %) mindate) coll)]
     (if (empty? fcoll)
         '()
       (filter (complement nil?)  
       (concat 
          (vector (fcoll true)) 
          (part-dates (fcoll false) 
                      (vector 
                       (dec month) 
                       (dec day)))))))))
  
(part-dates dates) ; -> ([[14 4] [12 4] [15 3]] [[13 3] [10 3]] [[1 1]])