anchor.diff:  (def clk (t/>> (t/clock) (t/new-duration 5 :minutes)))
   (t/with-clock clk (t/time))
   ----
  -
  -====
  +====
  +
   ====
   `year` - Give the year:
   [source.code,clojure]
  
positive.code: (def clk2 (t/atom (t/<< (t/clock) (t/new-duration 5 :minutes))))
  (t/reset-vals! clk clk2)
  ----
  
  ====
  
  ====
  
negative.code: ----
  (t/zoned-date-time "2000-01-01T00:00:00Z[Australia/Darwin]")
  ----
  ====
  