2026-01-04 clojure | Clojure Slack Archive

clojure 2026-01-04

Jim Newton 2026-01-04T11:54:29.351669Z

Happy new year everyone. I’m using some date-parsing code that chatgpt gave me some time ago which I think used to work. but after the new year started, it seems to fail. Can someone help me understand what’s happening. Here is the error I’m getting.

[:iso-string 2025-09-03T08:00:00+02:00 :now #object[java.time.Instant 0x4afbb6c2 2026-01-04T11:52:08.261119Z]]
Execution error (DateTimeParseException) at java.time.format.DateTimeFormatter/parseResolved0 (DateTimeFormatter.java:2046).
Text '2025-09-03T08:00:00+02:00' could not be parsed at index 19

Here is the code. it’s pretty simple.

(ns compute-grades
  (:import [ File]
           [java.time Instant]
           )
  (:require [clojure.string :refer [split starts-with? trim]]
            [clojure.pprint :refer [pprint]]
            [clojure.data.json :as json]
            [ :as io]
            [clojure.java.shell :refer [sh]])
  )

...

;; 
(defn future-date? [iso-string]
  (println [:iso-string iso-string :now (Instant/now)])
  (.isAfter (Instant/parse iso-string) (Instant/now)))

(defn past-date? [iso-string]
  (println [:iso-string iso-string :now (Instant/now)])
  (.isBefore (Instant/parse iso-string) (Instant/now)))

Jim Newton 2026-01-04T11:54:55.772999Z

I suppose I could ask chatgpt what the problem is.

Jim Newton 2026-01-04T11:56:46.785789Z

OK, chatgpt gave me a solution. I can try it.

daveliepmann 2026-01-04T12:15:56.139989Z

Both https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html#parse-java.lang.CharSequence- and https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#ISO_INSTANT require the string be in UTC. Your iso-string isn't; it has an offset.

✔️ 1

Jim Newton 2026-01-04T13:04:50.354369Z

The fix is:

;; 
(defn parse-iso->instant [s]
  (-> (OffsetDateTime/parse s)
      (.toInstant)))

(defn future-date? [iso-string]
  (.isAfter (parse-iso->instant iso-string) (Instant/now)))

(defn past-date? [iso-string]
  (.isBefore (parse-iso->instant iso-string) (Instant/now)))

Jim Newton 2026-01-04T13:23:51.997469Z

I wonder why it worked last year. it’s bizare.

p-himik 2026-01-04T13:56:07.629129Z

Perhaps the data was different?

Mathieu Lirzin 2026-01-04T20:22:07.608219Z

Hello I am wondering what is the purpose/role of the $install_dir/deps.edn file that is referenced in clojure bash script, this value is currently used to compute the classpath cache, however it does not seemed to be involved when computing the classpath itself because tools.deps is using another deps.edn that is packaged as a resource inside the tools.deps jar (https://github.com/clojure/tools.deps/blob/master/src/main/resources/clojure/tools/deps/deps.edn) , am I overlooking something ?

Alex Miller (Clojure team) 2026-01-04T20:23:40.929369Z

It's not used but continues to be shipped as some older tools relied on its presence

Mathieu Lirzin 2026-01-04T20:26:04.163449Z

thanks for the answer, do you remember the name of those older tools ?

Alex Miller (Clojure team) 2026-01-04T20:27:16.065679Z

the Datomic ion tooling was using a very old version of tools.deps that used it, but I think they have finally migrated off

Alex Miller (Clojure team) 2026-01-04T20:27:44.709769Z

I would say in the medium term it's likely to go away

👍 1

Mathieu Lirzin 2026-01-04T20:29:08.544749Z

thank again for your very quick answer, really appreciated !

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clojure 2026-01-04