com.antelmann.calendar
Class CalendarHelper

java.lang.Object
  com.antelmann.calendar.CalendarHelper

All Implemented Interfaces:

Serializable

public final class CalendarHelper
extends Object
implements Serializable

methods that require a calendar for calculation are synchronized, so they do not perform simultaneously

Author:

Holger Antelmann

See Also:

Serialized Form

Field Summary

static SimpleDateFormat

IETF_DATE_FORMAT the IETF date format is used in HTTP headers for displaying the date.

Constructor Summary

CalendarHelper()

CalendarHelper(Calendar calendar)

Method Summary

Date	addDays(Date date, int n)
int	age(Date birthday)
static Comparator<Date>	createBirthdayComparator() returns a newly created comparator that will compare the dates by ignoring the year
Date	dayBegin(Date d) returns a date that is set to the begin of the given day (daytime 12:00 a.m.)
Date	dayEnd(Date d)
int	dayInMonth(Date d)
int	dayOfWeek(Date date)
int	daysBetween(Date a, Date b) based on 24h difference adjusted by daylight savings time
int	daysInMonth(Date d)
int	differenceInDays(Date a, Date b) based on the date rather than the exact time in between
int	getBusinessYear(Date date, int monthOfYearBegin)
int	getBusinessYear(Date date, Month monthOfYearBegin)
Calendar	getCalendar() returns the currently used Calendar instance
Date	getDateForYear(int year)
int	getYear(Date date)
boolean	isAnniversary(Date anniversary, Date referenceDate)
boolean	isLastDayInMonth(Date d)
boolean	isWeekend(Date date)
int	month(Date d)
Date	monthBegin(Date d)
Date	monthEnd(Date d)
Date	nextDay(Date d) returns a date that is exactly a day later
Date	nextMonth(Date d) returns a date that is exactly a month later
Date	nextQuarter(Date d) returns a date that is exactly 3 months later
Date	nextWeek(Date d) returns a date that is exactly a week later
Date	nextYear(Date d) returns a date that is exactly a year later
int	offset(Date date) returns the offset that must be adjusted due to timezone specific daylight saving times
Date	previousDay(Date d)
Date	previousMonth(Date d)
Date	previousQuarter(Date d)
Date	previousWeek(Date d)
Date	previousYear(Date d)
Date	quarterBegin(Date d)
boolean	sameDay(Date d1, Date d2) returns true only if the two dates are within the same day given the default time zone
boolean	sameDayOfWeek(Date d1, Date d2)
boolean	sameMonth(Date d1, Date d2)
boolean	sameWeek(Date d1, Date d2)
boolean	sameYear(Date d1, Date d2)
void	setCalendar(Calendar calendar) by default, the standard GregorianCalendar is used
int	timeInDay(Date date) returns milliseconds from the beginning of the day
Date	weekBegin(Date d) week begins Monday here
int	weekInMonth(Date d)
int	weekInYear(Date d)
int	y2k(int twoDigitYear) returns an educated guess for the actual year that was meant
Date	yearBegin(Date d)
Date	yearEnd(Date d)
Date	yearToDate(int year)
long	zoneDiff(TimeZone tz, long timeInMillis) returns the difference in times from the currently used calendar to the given zone at the specified point in time

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

IETF_DATE_FORMAT

public static final SimpleDateFormat IETF_DATE_FORMAT

the IETF date format is used in HTTP headers for displaying the date. Since Java deprecated java.util.Date.parse(String), this offers an easy way to make the IETF date format work in any non-deprecated API.

Constructor Detail

CalendarHelper

public CalendarHelper()

CalendarHelper

public CalendarHelper(Calendar calendar)

Method Detail

getCalendar

public Calendar getCalendar()

returns the currently used Calendar instance

setCalendar

public void setCalendar(Calendar calendar)

by default, the standard GregorianCalendar is used

getYear

public int getYear(Date date)

getBusinessYear

public int getBusinessYear(Date date,
                           Month monthOfYearBegin)

getBusinessYear

public int getBusinessYear(Date date,
                           int monthOfYearBegin)

isWeekend

public boolean isWeekend(Date date)

dayOfWeek

public int dayOfWeek(Date date)

See Also:

Calendar.DAY_OF_WEEK

timeInDay

public int timeInDay(Date date)

returns milliseconds from the beginning of the day

See Also:

TimeInDay

zoneDiff

public long zoneDiff(TimeZone tz,
                     long timeInMillis)

returns the difference in times from the currently used calendar to the given zone at the specified point in time

offset

public int offset(Date date)

returns the offset that must be adjusted due to timezone specific daylight saving times

isAnniversary

public boolean isAnniversary(Date anniversary,
                             Date referenceDate)

sameDay

public boolean sameDay(Date d1,
                       Date d2)

returns true only if the two dates are within the same day given the default time zone

sameDayOfWeek

public boolean sameDayOfWeek(Date d1,
                             Date d2)

sameYear

public boolean sameYear(Date d1,
                        Date d2)

sameWeek

public boolean sameWeek(Date d1,
                        Date d2)

sameMonth

public boolean sameMonth(Date d1,
                         Date d2)

dayEnd

public Date dayEnd(Date d)

dayBegin

public Date dayBegin(Date d)

returns a date that is set to the begin of the given day (daytime 12:00 a.m.)

weekBegin

public Date weekBegin(Date d)

week begins Monday here

monthBegin

public Date monthBegin(Date d)

monthEnd

public Date monthEnd(Date d)

quarterBegin

public Date quarterBegin(Date d)

yearBegin

public Date yearBegin(Date d)

yearEnd

public Date yearEnd(Date d)

yearToDate

public Date yearToDate(int year)

nextDay

public Date nextDay(Date d)

returns a date that is exactly a day later

addDays

public Date addDays(Date date,
                    int n)

nextWeek

public Date nextWeek(Date d)

returns a date that is exactly a week later

nextMonth

public Date nextMonth(Date d)

returns a date that is exactly a month later

nextQuarter

public Date nextQuarter(Date d)

returns a date that is exactly 3 months later

nextYear

public Date nextYear(Date d)

returns a date that is exactly a year later

previousDay

public Date previousDay(Date d)

previousMonth

public Date previousMonth(Date d)

previousQuarter

public Date previousQuarter(Date d)

previousYear

public Date previousYear(Date d)

previousWeek

public Date previousWeek(Date d)

weekInYear

public int weekInYear(Date d)

weekInMonth

public int weekInMonth(Date d)

dayInMonth

public int dayInMonth(Date d)

daysInMonth

public int daysInMonth(Date d)

month

public int month(Date d)

isLastDayInMonth

public boolean isLastDayInMonth(Date d)

age

public int age(Date birthday)

createBirthdayComparator

public static Comparator<Date> createBirthdayComparator()

returns a newly created comparator that will compare the dates by ignoring the year

daysBetween

public int daysBetween(Date a,
                       Date b)

based on 24h difference adjusted by daylight savings time

differenceInDays

public int differenceInDays(Date a,
                            Date b)

based on the date rather than the exact time in between

getDateForYear

public Date getDateForYear(int year)

y2k

public int y2k(int twoDigitYear)

returns an educated guess for the actual year that was meant