anchor.diff:  ----
   (t/day-of-week "2018-01-01")
   ----
  -
  +====
  +
  +====
   `days` - Convert a duration into days
  -
   [source.code,clojure]
   ----
   (t/days (t/new-duration 24 :hours))
   ----
  -
  +====
  +
  +====
   `dec` - Give the prevous year:
  -
  -
   _This does not work_
  -
   [source.code,clojure]
   ----
   (t/dec (t/year))
   ----
  -
  -TBD
  -
  -difference
  -
  -divide
  -
  -
  -[source.code,clojure]
  -----
  -
  -----
  -
  +====
  +
  +====
  +`difference` - TBD
  +[source.code,clojure]
  +----
  +
  +----
  +====
  +
  +====
  +`divide` - Divide a duration by another duration:
  +[source.code,clojure]
  +----
  +(t/divide (t/new-duration 1 :days) (t/new-duration 1 :hours))
  +----
  +====
  +
  +====
   `divide-by` - Split an interval into even sections of time:
  -
   [source.code,clojure]
   ----
   (t/divide-by 10 {:tick/beginning (t/instant "2018-01-01T00:00")
   	         :tick/end (t/instant "2018-01-10T00:00")})
   ----
  -
  +====
  +
  +====
   `duration` - Give the duration of an interval:
  -
   [source.code,clojure]
   ----
   (t/duration {:tick/beginning (t/instant "2018-01-01T00:00")
   	     :tick/end (t/instant "2018-01-10T00:00")})
   ----
  -
  +====
  +
  +====
   `end` - Give the end instance of an interval:
  -
   [source.code,clojure]
   ----
   (t/end {:tick/beginning (t/instant "2018-01-01T00:00")
   	:tick/end (t/instant "2018-01-10T00:00")})
   ----
  -
  +====
  +
  +====
   `epoc` - Give the https://en.wikipedia.org/wiki/Unix_time[epoc]:
  -
   [source.code,clojure]
   ----
   (t/epoch)
   ----
  -
  +====
  +
  +====
   `extend` - Extend an interval by a duration:
  -
   [source.code,clojure]
   ----
   (t/extend {:tick/beginning (t/instant "2018-01-01T00:00")
              :tick/end (t/instant "2018-01-10T00:00")}
     (t/new-period 10 :weeks))
   ----
  -
  -TBD
  -
  -fields
  -
  -group-by
  -
  -hence
  -
  -
  -[source.code,clojure]
  -----
  -
  -----
  -
  +====
  +
  +====
  +`fields` -TBD
  +[source.code,clojure]
  +----
  +
  +----
  +====
  +
  +====
  +`group-by` - TBD
  +[source.code,clojure]
  +----
  +
  +----
  +====
  +
  +====
  +`hence` - TBD
  +[source.code,clojure]
  +----
  +
  +----
  +====
  +
  +====
   `hour` - Give the hour of the day:
  -
   [source.code,clojure]
   ----
   (t/hour (t/now))
   ----
  -
  +====
  +
  +====
   `hours` - Give a duration in hours:
  -
   [source.code,clojure]
   ----
   (t/hours (t/new-duration 2 :days))
   ----
  -
  +====
  +
  +====
   `in` - Give an instance in a time zone:
  -
  -[source.code,clojure]
  -----
  -(t/in (t/instant) "Australia/Darwin")
  -----
  -
  +[source.code,clojure]
  +----
  +(t/in (t/instant "2018-01-01T10:00") "Australia/Darwin")
  +----
  +====
  +
  +====
   `inc` - Give the next year:
  -
   [source.code,clojure]
   ----
   (t/inc (t/year))
   ----
  -
  +====
  +
  +====
   `inst` - Convert to `java.util.Date`:
  -
   [source.code,clojure]
   ----
   (t/inst)
   ----
  -
   [source.code,clojure]
   ----
   (t/inst (t/instant "2018-01-01T00:00"))
   ----
  -
  +====
  +
  +====
   `instant` - Convert to `java.time.Instant`:
  -
   [source.code,clojure]
   ----
   (t/instant (t/inst))
  
positive.code: ----
  (t/date "2018-01-01T00:00")
  ----
  
  `day-of-month` - Get the numerical day of the month:
  
  [source.code,clojure]
  ----
  (t/day-of-month)
  
negative.code: ----
  (t/date "2018-01-01")
  ----
  ====
  
  ====
  `date-time` - Get the date-time:
  [source.code,clojure]
  ----
  