A date and time library for Clojure, wrapping the Joda Time library. The Joda Time website says:
Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project.
If you are using Java 8 or later, consider using the built-in Java Time instead of Joda Time -- and look at clojure.java-time if you want a Clojure wrapper for that. See Converting from Joda Time to java.time for more details about the similarities and differences between the two libraries.
clj-time artifacts are released to Clojars.
If you are using Maven, add the following repository definition to your
Please open issues against the official clj-time repo on Github.
clj-time is a very thin wrapper around Joda Time. That means that if Joda Time has a "peculiar behavior", it's likely to be surfaced directly in
clj-time as well. A good example of this is
clj-time.format/unparse which simply calls Joda Time's
.print method -- and if the date passed in happens to be
nil, you silently get back the current date/time (many people would expect an exception!).
Please ask questions on the clj-time mailing list.
The main namespace for date-time operations in the
clj-time library is
(require '[clj-time.core :as t])
Create a DateTime instance with date-time, specifying the year, month, day, hour, minute, second, and millisecond:
(t/date-time 1986 10 14 4 3 27 456)
=> #<DateTime 1986-10-14T04:03:27.456Z>
Less-significant fields can be omitted:
(t/date-time 1986 10 14)
=> #<DateTime 1986-10-14T00:00:00.000Z>
Get the current time with
now and the start of the Unix epoch with
Once you have a date-time, use accessors like
second to access the corresponding fields:
(t/hour (t/date-time 1986 10 14 22))
The date-time constructor always returns times in the UTC time zone. If you want a time with the specified fields in a different time zone, use
(t/from-time-zone (t/date-time 1986 10 22) (t/time-zone-for-offset -2))
=> #<DateTime 1986-10-22T00:00:00.000-02:00>
If on the other hand you want a given absolute instant in time in a different time zone, use
(t/to-time-zone (t/date-time 1986 10 22) (t/time-zone-for-offset -2))
=> #<DateTime 1986-10-21T22:00:00.000-02:00>
In addition to
time-zone-for-offset, you can use the
default-time-zone functions and the
utc Var to construct or get
If you only want a date with no time component, consider using the
today functions. These return
LocalDate instances that do not have time components (and thus don't suffer from timezone-related shifting).
(t/local-date 2013 3 20)
=> #<LocalDate 2013-03-20>
before? determine the relative position of two DateTime instances:
(t/equal? (t/date-time 1986 10) (t/date-time 1986 10))
(t/after? (t/date-time 1986 10) (t/date-time 1986 9))
(t/before? (t/date-time 1986 9) (t/date-time 1986 10))
Often you will want to find a date some amount of time from a given date. For example, to find the time 1 month and 3 weeks from a given date-time:
(t/plus (t/date-time 1986 10 14) (t/months 1) (t/weeks 3))
=> #<DateTime 1986-12-05T00:00:00.000Z>
Interval is used to represent the span of time between two
DateTime instances. Construct one using
interval, then query them using
(t/within? (t/interval (t/date-time 1986) (t/date-time 1990))
in-minutes functions can be used to describe intervals in the corresponding temporal units:
(t/in-minutes (t/interval (t/date-time 1986 10 2) (t/date-time 1986 10 14)))
overlap function can be used to get an
Interval representing the overlap between two intervals:
(t/overlap (t/interval (t/date-time 1986) (t/date-time 1990))
(t/interval (t/date-time 1987) (t/date-time 1991)))
=> #<Interval 1987-01-01T00:00:00.000Z/1990-01-01T00:00:00.000Z>
today-at returns a moment in time at the given hour, minute and second on the current date UTC; not the current system date:
(t/today-at 12 00)
=> #<DateTime 2013-03-29T12:00:00.000Z>
(t/today-at 12 00 05)
=> #<DateTime 2013-03-29T12:00:05.000Z>
;; System clock says 11PM on 12/20/2016 UTC-5
(t/today-at 7 00 00)
=> #<DateTime 2016-12-21T7:00:00.000Z>
If you need to parse or print date-times, use
(require '[clj-time.format :as f])
Parsing and printing are controlled by formatters. You can either use one of the built in ISO8601 formatters or define your own, e.g.:
(def built-in-formatter (f/formatters :basic-date-time))
(def custom-formatter (f/formatter "yyyyMMdd"))
To see a list of available built-in formatters and an example of a date-time printed in their format:
mm is minutes,
MM is months,
ss is seconds and
SS is milliseconds. You can find a complete list of patterns on the Joda Time website.
Once you have a formatter, parsing and printing are straightforward:
(f/parse custom-formatter "20100311")
=> #<DateTime 2010-03-11T00:00:00.000Z>
(f/unparse custom-formatter (t/date-time 2010 10 3))
To parse dates in multiple formats and format dates in just one format, you can do this:
(def multi-parser (f/formatter (t/default-time-zone) "YYYY-MM-dd" "YYYY/MM/dd"))
(f/unparse multi-parser (f/parse multi-parser "2012-02-01"))
(f/unparse multi-parser (f/parse multi-parser "2012/02/01"))
Note: Joda Time's
.print method accepts a null date/time object and substitutes the current date/time, so
(f/unparse my-fmt nil) will not throw an exception -- it will just silently return the current date/time!
clj-time.coerce contains utility functions for coercing Joda
DateTime instances to and from various other types:
(require '[clj-time.coerce :as c])
For example, to convert a Joda
DateTime to and from a Java
(c/to-long (t/date-time 1998 4 25))
=> #<DateTime 1998-04-25T00:00:00.000Z>
And by the magic of protocols you can pass in an isoformat string and get the unix epoch milliseconds:
There are also conversions to and from
from-sql-time) and several other types.
clj-time.local contains functions for working with local time without having to shift to/from utc, the preferred time zone of clj-time.core.
(require '[clj-time.local :as l])
Get the current local time with
Get a local date-time instance retaining the time fields with
The following all return 1986-10-14 04:03:27.246 with the local time zone.
(l/to-local-date-time (clj-time.core/date-time 1986 10 14 4 3 27 246))
The dynamic var
*local-formatters* contains a map of local formatters for parsing and printing. It is initialized with all the formatters in clj-time.format localized.
to-local-date-time for strings uses
*local-formatters* to parse.
Format an obj using a formatter in
*local-formatters* corresponding to the format-key passed in with
(l/format-local-time (l/local-now) :basic-date-time)
clj-time.periodic/periodic-seq returns an infinite sequence of instants separated by a time period starting with the given point in time:
(require '[clj-time.periodic :as p])
(require '[clj-time.core :as t])
;; returns 10 instants starting with current time separated
;; by 12 hours
(take 10 (p/periodic-seq (t/now) (t/hours 12)))
In particular, if you ask for a sequence of instants separated by a month, you will get dates where the month increases each time (rather than being, say, 30 days apart).
clj-time.predicates comes with a set of handy predicates to check for common conditions. For instance:
(require '[clj-time.core :as t])
(require '[clj-time.predicates :as pr])
(pr/monday? (t/date-time 1999 9 9))
(pr/january? (t/date-time 2011 1 1))
(pr/weekend? (t/date-time 2014 1 26))
(pr/weekday? (t/date-time 2014 1 26))
(pr/last-day-of-month? (t/date-time 2014 1 26))
(pr/first-day-of-month? (t/date-time 2014 1 26))
clj-time.jdbc registers protocol extensions so you don’t have to use
clj-time.coerce yourself to coerce to and from SQL timestamps.
From the REPL:
In your project:
; They're registered and ready to use.
Now you can use
org.joda.time.DateTime objects when "writing" to the database in place of
java.sql.Timestamp objects, and expect
org.joda.time.DateTime objects when "reading" where you would have previously expected
Running the tests:
$ rm -f test/readme.clj && lein test-all && lein test-readme
(assumes Leiningen 2.x)
The complete API documentation is also available (codox generated).
Released under the MIT License: https://github.com/clj-time/clj-time/blob/master/MIT-LICENSE.txt