Java in a Nutshell, 5th Edition

Name

Calendar

Synopsis

This abstract class defines methods that perform date and time arithmetic. It also includes methods that convert dates and times to and from the machine-usable millisecond format used by the Date class and units such as minutes, hours, days, weeks, months, and years that are more useful to humans. As an abstract class, Calendar cannot be directly instantiated. Instead, it provides static getInstance( ) methods that return instances of a Calendar subclass suitable for use in a specified or default locale with a specified or default time zone. See also Date, DateFormat, and TimeZone.

Calendar defines a number of useful constants. Some of these are values that represent days of the week and months of the year. Other constants, such as HOUR and DAY_OF_WEEK, represent various fields of date and time information. These field constants are passed to a number of Calendar methods, such as get( ) and set( ), in order to indicate what particular date or time field is desired.

setTime( ) and the various set( ) methods set the date represented by a Calendar object. The add( ) method adds (or subtracts) values to a calendar field, incrementing the next larger field when the field being set rolls over. roll( ) does the same, without modifying anything but the specified field. before( ) and after( ) compare two Calendar objects. Many of the methods of the Calendar class are replacements for methods of Date that have been deprecated as of Java 1.1. While the Calendar class ...