7.0.7 + Java 25: Fix for WARNING: Use of the three-letter time zone ID ... is deprecated and it will be removed in a future release by codeconsole · Pull Request #15432 · apache/grails-core

codeconsole · 2026-02-21T23:10:39Z

When using Java 25, all grails applications startup with

> Task :bootRun
WARNING: Use of the three-letter time zone ID "ACT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AGT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "ART" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "BET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "BST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CAT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CNT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CTT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "EAT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "ECT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "EST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "HST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "IET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "IST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "JST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "MIT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "MST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "NET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "NST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PLT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PNT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PRT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "SST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "VST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "BET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "ART" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "JST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "VST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "IET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CNT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PLT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PNT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "EST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "EAT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "ECT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "PRT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CTT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "SST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "MST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "NST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "HST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "ACT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "BST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "IST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CST" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "NET" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "AGT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "CAT" is deprecated and it will be removed in a future release
WARNING: Use of the three-letter time zone ID "MIT" is deprecated and it will be removed in a future release
Grails application running at http://localhost:8090 in environment: development

This is due to the legacy FastDateFormat. This PR switches to java.time instead while maintaining backward compatibility.
The messages no longer occur after this fix.

…ed and it will be removed in a future release

jdaugherty · 2026-02-21T23:11:49Z

We already merged the fix for this ...

jdaugherty · 2026-02-21T23:12:34Z

I guess this is fixing it by changing to the new api instead of the lang update?

codeconsole · 2026-02-21T23:13:13Z

I guess this is fixing it by changing to the new api instead of the lang update?

yeah, but are you sure updating the new api still fixes it?

codeconsole · 2026-02-21T23:15:53Z

@jdaugherty if it was already fixed, why am I still getting the error using the latest 7.1.0-SNAPSHOT?

jdaugherty · 2026-02-21T23:17:41Z

#15417 was merged 11hrs ago, I don't think we have merged up to 7.1.x yet

jdaugherty · 2026-02-22T01:44:30Z

I''ve merged these changes up, can you retest before your changes and see if that fixed it? We will still need to take this API to ultimately update the usages, but I assume we'll do that in 7.1.x instead of 7.0.x? @jamesfredley

jdaugherty · 2026-02-25T18:36:18Z

...converters/src/main/groovy/org/grails/web/converters/marshaller/json/CalendarMarshaller.java

     */
    public CalendarMarshaller() {
-        this(FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", TimeZone.getTimeZone("GMT"), Locale.US));
+        this.legacyFormatter = null;


Are there any known performance problems with the java.time.DateTimeFormatter vs the FastDateTimeFormatter?

DateTimeFormatter is ~15% faster based on the following

https://gist.github.com/akostadinov/670a4dc93485128efb6023f5fa319521

https://martin-grigorov.medium.com/compare-performance-of-javas-simpledateformat-against-datetimeformatter-31be58cadf1d

jdaugherty

It doesn't look like any tests were added for this change and the default has been changed. This probably should be a 7.1 change.

bito-code-review · 2026-02-25T18:37:11Z

This question isn’t related to the pull request. I can only help with questions about the PR’s code or comments.

Copilot

Pull request overview

This PR addresses Java 25 deprecation warnings by migrating from Apache Commons FastDateFormat (which uses deprecated three-letter timezone IDs) to Java's java.time.format.DateTimeFormatter API. The change maintains backward compatibility by preserving support for custom formatters through a legacyFormatter field.

Changes:

Replaced FastDateFormat with DateTimeFormatter in date/calendar marshallers
Added backward compatibility support for custom formatters via legacyFormatter field
Switched from deprecated three-letter timezone IDs to proper timezone handling

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
grails-converters/src/main/groovy/org/grails/web/converters/marshaller/xml/DateMarshaller.java	Migrated XML date marshaller to use DateTimeFormatter with system default timezone
grails-converters/src/main/groovy/org/grails/web/converters/marshaller/json/DateMarshaller.java	Migrated JSON date marshaller to use DateTimeFormatter with UTC timezone
grails-converters/src/main/groovy/org/grails/web/converters/marshaller/json/CalendarMarshaller.java	Migrated JSON calendar marshaller to use DateTimeFormatter with UTC timezone

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Copilot · 2026-02-25T18:40:44Z

grails-converters/src/main/groovy/org/grails/web/converters/marshaller/xml/DateMarshaller.java


-    private final Format formatter;
+    private static final DateTimeFormatter DEFAULT_FORMATTER =
+            DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS z")


The date pattern has been changed from "yyyy-MM-dd HH:mm:ss.S z" (single 'S' for milliseconds) to "yyyy-MM-dd HH:mm:ss.SSS z" (triple 'S'). This changes the output format and is not backward compatible. A date with milliseconds value 5 would previously be formatted as "5" but will now be formatted as "005". This could break existing clients that parse these dates. Consider using the original pattern "yyyy-MM-dd HH:mm:ss.S z" to maintain backward compatibility.

Suggested change

DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS z")

DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S z")

We need to revert or justify and add documentation for this change.

jamesfredley · 2026-02-27T21:55:52Z

Since this doesn't fix a bug, but resolves annoying log lines when running on Java 25 by changing production code, I think this would be safer in 7.1.x.

Cover default DateTimeFormatter output, millisecond padding, UTC conversion, legacy Format fallback, and supports() behavior for json/DateMarshaller, json/CalendarMarshaller, and xml/DateMarshaller. Assisted-by: Claude Code <Claude@Claude.ai>

jdaugherty · 2026-02-27T22:04:19Z

@jamesfredley shouldn't we add functional / integration tests for this too given the impact? we're only testing the lower level stuff with this pr

Add DateMarshallerController and DateMarshallerSpec integration tests to grails-test-examples/app1, exercising the DateTimeFormatter-based marshallers end-to-end through the Grails converters pipeline. Tests cover: - JSON Date marshalling (ISO 8601 UTC format) - JSON Calendar marshalling (ISO 8601 UTC format) - XML Date marshalling (system default timezone format) - 3-digit millisecond padding (.SSS) for both JSON and XML - URL extension-based content negotiation (.json, .xml) Assisted-by: Claude Code <Claude@Claude.ai>

Fix for WARNING: Use of the three-letter time zone ID ... is deprecat…

2fcf832

…ed and it will be removed in a future release

github-project-automation bot added this to Apache Grails Feb 21, 2026

codeconsole requested a review from matrei February 21, 2026 23:10

codeconsole assigned sbglasius, jdaugherty and jamesfredley Feb 21, 2026

codeconsole requested review from jamesfredley, jdaugherty and sbglasius February 21, 2026 23:11

codeconsole unassigned sbglasius, jdaugherty and jamesfredley Feb 21, 2026

fix formatting

ba0835b

Merge branch '7.0.x' into time-zone-warning-fix

6c3e9b1

jdaugherty reviewed Feb 25, 2026

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jdaugherty requested a review from Copilot February 25, 2026 18:37

Copilot started reviewing on behalf of jdaugherty February 25, 2026 18:37 View session

Copilot AI reviewed Feb 25, 2026

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Merge branch '7.0.x' into time-zone-warning-fix

66ed763

jamesfredley added 2 commits February 27, 2026 18:20

Merge branch '7.0.x' into time-zone-warning-fix

e4b640a

	DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS z")
	DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S z")

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