Joda-Time provides a quality replacement for the Java date and time classes. The standard date and time classes prior to Java SE 8 are poor. By tackling this problem head-on, Joda-Time has become the de facto standard date and time library for Java. The 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.