Calendar

Calendar

java.util

---

Java 1.1

cloneable serializable comparable

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 converts a time value to its various hour, day, month, and other fields, it is not intended to present those fields in a form suitable for display to the end user . That function is performed by the java.text.DateFormat class, which handles internationalization issues.

Calendar implements Comparable in Java 5.0, but not in earlier releases.

Figure 16-9. java.util.Calendar

 public abstract class  Calendar  implements Serializable, Cloneable, Comparable<Calendar> {  // Protected Constructors  protected  Calendar  ( );        protected  Calendar  (TimeZone  zone  , Locale  aLocale  );  // Public Constants  public static final int  AM  ;  =0  public static final int  AM_PM  ;  =9  public static final int  APRIL  ;  =3  public static final int  AUGUST  ;  =7  public static final int  DATE  ;  =5  public static final int  DAY_OF_MONTH  ;  =5  public static final int  DAY_OF_WEEK  ;  =7  public static final int  DAY_OF_WEEK_IN_MONTH  ;  =8  public static final int  DAY_OF_YEAR  ;  =6  public static final int  DECEMBER  ;  =11  public static final int  DST_OFFSET  ;  =16  public static final int  ERA  ;  =0  public static final int  FEBRUARY  ;  =1  public static final int  FIELD_COUNT  ;  =17  public static final int  FRIDAY  ;  =6  public static final int  HOUR  ;  =10  public static final int  HOUR_OF_DAY  ;  =11  public static final int  JANUARY  ;  =0  public static final int  JULY  ;  =6  public static final int  JUNE  ;  =5  public static final int  MARCH  ;  =2  public static final int  MAY  ;  =4  public static final int  MILLISECOND  ;  =14  public static final int  MINUTE  ;  =12  public static final int  MONDAY  ;  =2  public static final int  MONTH  ;  =2  public static final int  NOVEMBER  ;  =10  public static final int  OCTOBER  ;  =9  public static final int  PM  ;  =1  public static final int  SATURDAY  ;  =7  public static final int  SECOND  ;  =13  public static final int  SEPTEMBER  ;  =8  public static final int  SUNDAY  ;  =1  public static final int  THURSDAY  ;  =5  public static final int  TUESDAY  ;  =3  public static final int  UNDECIMBER  ;  =12  public static final int  WEDNESDAY  ;  =4  public static final int  WEEK_OF_MONTH  ;  =4  public static final int  WEEK_OF_YEAR  ;  =3  public static final int  YEAR  ;  =1  public static final int  ZONE_OFFSET  ;  =15   // Public Class Methods  public static Locale[ ]  getAvailableLocales  ( );  synchronized  public static Calendar  getInstance  ( );        public static Calendar  getInstance  (Locale  aLocale  );        public static Calendar  getInstance  (TimeZone  zone  );        public static Calendar  getInstance  (TimeZone  zone  , Locale  aLocale  );  // Public Instance Methods  public abstract void  add  (int  field  , int  amount  );        public boolean  after  (Object  when  );        public boolean  before  (Object  when  );        public final void  clear  ( );        public final void  clear  (int  field  );        public int  get  (int  field  );  1.2  public int  getActualMaximum  (int  field  );  1.2  public int  getActualMinimum  (int  field  );        public int  getFirstDayOfWeek  ( );        public abstract int  getGreatestMinimum  (int  field  );        public abstract int  getLeastMaximum  (int  field  );        public abstract int  getMaximum  (int  field  );        public int  getMinimalDaysInFirstWeek  ( );        public abstract int  getMinimum  (int  field  );        public final Date  getTime  ( );        public long  getTimeInMillis  ( );        public TimeZone  getTimeZone  ( );        public boolean  isLenient  ( );        public final boolean  isSet  (int  field  );  1.2  public void  roll  (int  field  , int  amount  );        public abstract void  roll  (int  field  , boolean  up  );        public void  set  (int  field  , int  value  );        public final void  set  (int  year  , int  month  , int  date  );        public final void  set  (int  year  , int  month  , int  date  , int  hourOfDay  , int  minute  );        public final void  set  (int  year  , int  month  , int  date  , int  hourOfDay  , int  minute  ,          int  second  );        public void  setFirstDayOfWeek  (int  value  );        public void  setLenient  (boolean  lenient  );        public void  setMinimalDaysInFirstWeek  (int  value  );        public final void  setTime  (Date  date  );        public void  setTimeInMillis  (long  millis  );        public void  setTimeZone  (TimeZone  value  );  // Methods Implementing Comparable   5.0  public int  compareTo  (Calendar  anotherCalendar  );  // Public Methods Overriding Object  public Object  clone  ( );        public boolean  equals  (Object  obj  );  1.2  public int  hashCode  ( );        public String  toString  ( );  // Protected Instance Methods  protected void  complete  ( );        protected abstract void  computeFields  ( );        protected abstract void  computeTime  ( );        protected final int  internalGet  (int  field  );  // Protected Instance Fields  protected boolean  areFieldsSet  ;        protected int[ ]  fields  ;        protected boolean[ ]  isSet  ;        protected boolean  isTimeSet  ;        protected long  time  ;   } 

Subclasses

GregorianCalendar

Passed To

java.text.DateFormat.setCalendar( ) , javax.xml.datatype.Duration.{addTo( ) , getTimeInMillis( ) , normalizeWith( )}

Returned By

java.text.DateFormat.getCalendar( )

Type Of

java.text.DateFormat.calendar