Joda-Time

Joda-Time provides a quality replacement for the date and time classes provided with the official JDK distribution, which suffer from very bad designed, have had numerous bugs and have odd performance effects. The library helps you to solve many of the most common date/time issues faced by the Java developer. The Joda-Time design allows for multiple calendar systems, while still providing a simple API. The 'default' calendar is the ISO8601 standard which is used by XML. The Gregorian, Julian, Buddhist, Coptic, Ethiopic and Islamic systems are also included, and we welcome further additions. Supporting classes include time zone, duration, format and parsing.

Features

  • Easy to Use. Calendar makes accessing 'normal' dates difficult, due to the lack of simple methods. Joda-Time has straightforward field accessors such as getYear() or getDayOfWeek().
  • Easy to Extend. The JDK supports multiple calendar systems via subclasses of Calendar. This is clunky, and in practice it is very difficult to write another calendar system. Joda-Time supports multiple calendar systems via a pluggable system based on the Chronology class.
  • Easy to Extend. The JDK supports multiple calendar systems via subclasses of Calendar. This is clunky, and in practice it is very difficult to write another calendar system. Joda-Time supports multiple calendar systems via a pluggable system based on the Chronology class.
  • Comprehensive Feature Set. The library is intended to provide all the functionality that is required for date-time calculations. It already provides out-of-the-box features, such as support for oddball date formats, which are difficult to replicate with the JDK.
  • Up-to-date Time Zone calculations. The time zone implementation is based on the public tz database, which is updated several times a year. New Joda-Time releases incorporate all changes made to this database. Should the changes be needed earlier, manually updating the zone data is easy.
  • Calendar support. The library currently provides 8 calendar systems. More will be added in the future.
  • Easy interoperability. The library internally uses a millisecond instant which is identical to the JDK and similar to other common time representations. This makes interoperability easy, and Joda-Time comes with out-of-the-box JDK interoperability.
  • Better Performance Characteristics. Calendar has strange performance characteristics as it recalculates fields at unexpected moments. Joda-Time does only the minimal calculation for the field that is being accessed.
  • Good Test Coverage. Joda-Time has a comprehensive set of developer tests, providing assurance of the library's quality.
  • Complete Documentation. There is a full User Guide which provides an overview and covers common usage scenarios. The javadoc is extremely detailed and covers the rest of the API.
  • Maturity. The library has been under active development since 2002. Although it continues to be improved with the addition of new features and bug-fixes, it is a mature and reliable code base. A number of related projects are now available.v
  • Open Source. Joda-Time is licenced under the business friendly Apache License Version 2.0.