Java Date vs Calendar

Date is a simpler class and is mainly there for backward compatibility reasons. If you need to set particular dates or do date arithmetic, use a Calendar. Calendars also handle localization. The previous date manipulation functions of Date have since been deprecated.

Personally I tend to use either time in milliseconds as a long (or Long, as appropriate) or Calendar when there is a choice.

Both Date and Calendar are mutable, which tends to present issues when using either in an API.

The best way for new code (if your policy allows third-party code) is to use the Joda Time library.

Both, Date and Calendar, have so many design problems that neither are good solutions for new code.