(use test)
(use simple-units)

(make-units time s
  m 60
  h (60 m)
  d (24 h)
  ms (0.0001 s)
  us (0.0001 ms))

(test 84203 (+ (make-quantity 23 h) (make-quantity 23 m) (make-quantity 23 s)))

(define time-units
  (make-units* time s
    m 60
    h (60 m)
    d (24 h)
    ms (0.0001 s)
    us (0.0001 ms)))

(test 84203
  (+ (make-quantity 23 h time-units)
     (make-quantity 23 m time-units)
     (make-quantity 23 s time-units)))