JodaOrg/joda-time

> The de facto Java date-time library of the pre-Java-8 era — now in maintenance-only mode, superseded by its own descendant java.time.

GitHub repo · Official website · License: Apache-2.0

Overview

Joda-Time is a date and time library for Java, created by Stephen Colebourne to replace the deeply flawed java.util.Date and java.util.Calendar classes that shipped with the JDK. Its core design ideas — immutable value types, a clean separation between instants, partials (like LocalDate), durations, and periods, and pluggable chronologies (ISO, Gregorian, Julian, Buddhist, Coptic, Islamic, and others) — became the reference model for how date-time handling should work in a typed language.

The defining fact about Joda-Time in 2026 is that it is explicitly finished. The README states it "is no longer in active development except to keep timezone data up to date"¹. This is not abandonment but a rare, deliberate wind-down: the same author, Stephen Colebourne, went on to lead JSR-310, which brought java.time into Java SE 8 in 2014². java.time is essentially Joda-Time's successor, redesigned with the benefit of hindsight (nanosecond precision, a cleaner nullable story, Instant/ZonedDateTime/LocalDate split). The project's own maintainers ask Java 8+ users to migrate.

So the tension here is unusual: Joda-Time is high quality, battle-tested, and still pulled by an enormous swath of the Maven ecosystem, yet using it in new code is a documented mistake if you are on a modern JDK. It survives mostly as a transitive dependency and in legacy codebases that have not paid down the migration.

Getting Started

Maven:

<dependency>
  <groupId>joda-time</groupId>
  <artifactId>joda-time</artifactId>
  <version>2.14.2</version>
</dependency>

Gradle:

implementation 'joda-time:joda-time:2.14.2'

Minimal example:

import org.joda.time.*;

LocalDate today = LocalDate.now();
LocalDate newYear = today.plusYears(1).withDayOfYear(1);
Days remaining = Days.daysBetween(today, newYear);

DateTime now = new DateTime(DateTimeZone.forID("Europe/London"));
Period rental = new Period().withDays(2).withHours(12);
boolean overdue = now.plus(rental).isBeforeNow();

Note the classic footgun preserved from the API: months are 1-based (getMonthOfYear() == 2 is February), which is more sane than java.util.Calendar's 0-based months but differs from some ports.

Architecture / How It Works

Joda-Time separates the domain into a small number of orthogonal concepts:

• Instants — DateTime, Instant, DateMidnight (deprecated): a specific

point on the timeline, tied to a chronology and zone.

• Partials — LocalDate, LocalTime, LocalDateTime, YearMonth,

MonthDay: a date/time with no zone, representing "some 3 PM" rather than a specific instant.

• Durations vs Periods — a Duration is an exact millisecond span; a

Period is a human span ("2 months, 3 days") whose millisecond length depends on when it is applied. Conflating these is the most common date-math bug and Joda-Time was one of the first libraries to force the distinction into the type system.

• Chronology — the pluggable calendar-system engine. ISOChronology is the

default; every field operation (monthOfYear(), dayOfWeek()) routes through the active chronology, which is how alternate calendars are supported without branching in user code.

Almost all core types are immutable and thread-safe; mutation methods return new instances (withDayOfYear, plusDays). This immutability was a deliberate reaction to the mutable, footgun-heavy java.util.Calendar.

Time-zone data comes from the IANA TZDB, compiled into the jar. This is the one part of the library that still changes: point releases (2.x) exist almost entirely to ship updated zone rules as governments alter DST and offsets¹.

Production Notes

The timezone-data coupling is the real operational concern. Because zone rules are baked into the jar, an old Joda-Time pin will silently compute wrong local times after a country changes its DST policy. Keep the dependency current even though the code is "finished" — the whole point of ongoing releases is the TZDB refresh. External zone data can be supplied via DateTimeZone.setProvider, but almost nobody does.

Migration to java.time is the dominant long-term cost. The APIs look similar but are not drop-in: Joda's DateTime maps loosely to java.time.ZonedDateTime, LocalDate/LocalTime/LocalDateTime names collide but have subtly different semantics, and Joda Period/Duration do not line up one-to-one with java.time.Period/Duration. Teams typically bridge at serialization boundaries (Jackson has both jackson-datatype-joda and jackson-datatype-jsr310) and migrate module by module.

Null and parsing behavior differ from the JDK. Joda-Time formatters (DateTimeFormat.forPattern) are lenient in places java.time's DateTimeFormatter is strict, so a mechanical port can change which inputs parse.

Android: for minSdk below 26, java.time is unavailable natively; the common replacement is not Joda-Time but ThreeTenABP, a backport of JSR-310, which the README itself recommends¹. There was also a stripped-down joda-time-android fork built for method-count-sensitive Android apps, but ThreeTenABP is now the standard answer.

Security/support: vulnerability handling is routed through Tidelift rather than public GitHub issues¹.

When to Use / When Not

Use when:

• You are on Java 6/7 and cannot use java.time at all.
• You are maintaining an existing Joda-Time codebase and a full migration is not

yet justified — keep the dependency patched for TZDB updates.

• A dependency you rely on exposes Joda types in its public API.

Avoid when:

• You are writing new code on Java 8 or later — use java.time (JSR-310), which

is the maintainer-endorsed successor.

• You need nanosecond precision (Joda-Time is millisecond-resolution).
• You are on modern Android (minSdk 26+) — use java.time directly; below that,

use ThreeTenABP.

Alternatives

• java.time (JSR-310, part of the JDK) — the successor by the same author; use it for any new code on Java 8+.
• ThreeTen/threetenbp — Stephen Colebourne's standalone backport of java.time for Java 6/7; use when you want JSR-310 semantics on an old JDK.
• JakeWharton/ThreeTenABP — Android packaging of threetenbp with lazy TZDB loading; use for Android minSdk < 26.
• apache/commons-lang (DateUtils) — use only for small utility helpers over legacy java.util.Date, not as a full date model.

History

References

1. ^ Joda-Time README and project home page — migration guidance, maintenance

status, TZDB update policy, Android/ThreeTenABP recommendation, Tidelift security contact. https://www.joda.org/joda-time/

1. ^ JSR-310 "Date and Time API", delivered in Java SE 8 (2014), led by Stephen

Colebourne — the maintainer-endorsed successor to Joda-Time. https://jcp.org/en/jsr/detail?id=310

Tags

java, date-time, jvm, immutable, timezone, calendar-systems, jsr-310, legacy, maintenance-mode, library