Need to know

• a temporal is an entity that relates to the timeline (LocalDate, Instant, ZonedDateTime etc)
• a temporal-amount is an entity representing a quantity of time - either a Duration or a Period
• a basic understanding of the main entities of java.time is required to use tick
• Where tick doesn’t provide the API you need, drop to cljc.java-time

Naming (compared to java.time)

• LocalDate => date
• LocalDateTime => date-time
• LocalTime => time
• java.util.Date => inst
• js/Date => inst

otherwise all camel-case equivalents of java.time names

Temporals

All functions relating to temporals have names in the singular, whereas functions relating to temporal-amounts have names in the plural, e.g. (t/hour x) vs (t/hours x)

Construction

Now

zero-arity function for the required type

(t/date), (t/zoned-date-time), (t/instant), (t/...)

Temporarily change what clock is used to get the now or where information with with-clock

(t/with-clock
  (t/zoned-date-time "2023-08-23T20:00-10:00[Pacific/Honolulu]") 
   (t/date)) 
 ; => returns (t/date "2023-08-23")

Extraction / Conversion

(t/date (t/zoned-date-time))
(t/hour (t/zoned-date-time))
(t/inst (t/zoned-date-time))

set hours and smaller to zero

(t/truncate (t/instant) :hours) 

Combining parts

(-> (t/date)
    (t/at "00:00")
    (t/in "UTC"))

(-> (t/time "10:10")
    (t/on (t/date)))

; 'set' or 'adjust' a specific field
(t/with (t/date) (t/year 3030))

from/to Strings

ISO-formatted

(t/instant "2020-02-02T00:00:00Z")
(t/... "2020...")

(str (t/instant))

Custom formats

(t/parse-... "2021-...", (t/formatter "pattern"))

(t/format (t/date) (t/formatter "pattern"))

from numbers

(t/new-date 2020 2 2) 
(t/new-... )

round-trip to/from epoch millis

(-> (t/instant) (cljc.java-time.instant/to-epoch-milli) (t/instant))

Relative temporals aka shifting

 (t/>> (t/instant) (t/of-hours 2))
 (t/<< ...)

Temporal Amounts

Construction

(t/of-hours 24) => Duration
(t/of-days 1) => Period
(t/of-..)

From temporals

(t/between a b) ;=> returns temporal-amount
(t/between a b :days) ;=> returns number

Arithmetic

(t/+ (t/of-minutes 5) (t/of-minutes 5) (t/of-minutes 5), ...)
(t/- ...)

Extract parts

function names in plural

(t/millis ...)
(t/days ...)

Comparison

t/<, t/<=, t/=, ...
t/max, t/max-by, t/min, t/min-by

contains/coincidence

(t/coincident? temporal-start temporal-end a-temporal))

Type Predicates

(t/date-time? x)
(t/...? x)

Units

t/APRIL,
t/DECEMBER ...

t/FRIDAY, t/MONDAY...

(keys t/unit-map) => :nanos :days :seconds ...