Dates (The ZKoss Common Library 8.6.0.1 API)

java.lang.Object
- org.zkoss.util.Dates

```
public class Dates
extends Object
```
Utilities for java.util.Date

Author:

henrichen, tomyeh

Constructor Summary

Constructors
Constructor and Description

Dates()

Constructors
Constructor and Description
`Dates()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static Date`	`add(Date when, TimeZone tz, int field, int amount)` Date Arithmetic function.
`static Date`	`beginOfDate(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the beginning date of the specified date and TimeZone.
`static Date`	`beginOfMonth()` Return the beginning date of this month.
`static Date`	`beginOfMonth(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the beginning date of the month of the specified date and TimeZone.
`static Date`	`beginOfYear()` Return the beginning date of this year.
`static Date`	`beginOfYear(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the beginning date of the month of the specified date and TimeZone.
`static int`	`dayMonthOfDate(Date when, TimeZone tz)` Get the day of month of a date.
`static Date`	`endOfDate(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the last millisecond date of the specified date and TimeZone.
`static Date`	`endOfMonth()` Return the ending date of this month.
`static Date`	`endOfMonth(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the ending date of the month of the specified date and TimeZone.
`static Date`	`endOfYear()` Return the ending date of this year.
`static Date`	`endOfYear(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the ending date of the month of the specified date and TimeZone.
`static long`	`getTimezoneOffset(TimeZone timezone, Date date)` Returns the timezone offset.
`static boolean`	`isBeginOfMonth(Date when, TimeZone tz)` Whether the given date in the specified TimeZone is the first day of that month.
`static boolean`	`isEndOfMonth(Date when, TimeZone tz)` Whether the given date in the specified TimeZone is the last day of that month.
`static boolean`	`isRounded(Date date, int precision)` Tests whether a date is rounded.
`static int`	`localizedYearOfDate(Date when, Locale locale, TimeZone tz)` Get the year of a date in the specified locale.
`static Date`	`merge(Date datePart, Date timePart, TimeZone tz)` merge the date part and time part of two specified dates into a date.
`static int`	`monthOfDate(Date when, TimeZone tz)` Get the month of a date.
`static int`	`monthOfDatePlus1(Date when, TimeZone tz)` Get the month of a date.
`static Date`	`now()` Returns the current time without rounding.
`static Date`	`now(int precision)` Returns the current time but rounding to the specified precision of milliseconds.
`static Date`	`previousDate(Date when)` Given a date, return the previous date of the given date (24 hrs before).
`static Date`	`round(Date date, int precision)` Truncates date to the nearest precision milliseconds.
`static long`	`round(long time, int precision)` Rounds a date represented in long to the specified precision of milliseconds.
`static long`	`subtract(Date date2, TimeZone tz, int field, Date date1)` Date Arithmetic function (date2 - date1).
`static Date`	`today()` Returns today by setting time to 0:0:0.
`static short`	`twoMonthShort()` Return the ending date of this year.
`static short`	`twoMonthShort(Date when, TimeZone tz)` Given a date, a proper TimeZone, return the two month int.
`static int`	`yearOfDate(Date when, TimeZone tz)` Get the year of a date.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Dates
```
public Dates()
```
- Method Detail
  - round
```
public static final Date round(Date date,
                               int precision)
```
    Truncates date to the nearest precision milliseconds. MS SQLServer2000 with only the maximum accuracy of 1/300 seconds would not be able to store up to one millisecond accuracy. That is, User must round the millisecond to some less precisions; or the data in that db would be inconsistent with that in memory. It is useful to store a Date object in a database. Without rounding, if you want to get it back and compare with the one in the memory. See now(int) for details.
    
    Parameters:
    
    precision - the divider of the precision(e.g. 10 for precision of 10 milliseconds;i.e. all millisecond less than 10 would be truncated)
    
    See Also:
    
    now(int), round(long, int)
  - round
```
public static final long round(long time,
                               int precision)
```
    Rounds a date represented in long to the specified precision of milliseconds.
    
    Parameters:
    
    time - the date represented in long.
    
    precision - the divider of the precision(e.g. 10 for precision of 10 milliseconds;i.e. all millisecond less than 10 would be truncated)
    
    See Also:
    
    now(int), round(Date, int)
  - isRounded
```
public static final boolean isRounded(Date date,
                                      int precision)
```
    Tests whether a date is rounded. It is mainly used for debugging.
  - now
```
public static final Date now(int precision)
```
    Returns the current time but rounding to the specified precision of milliseconds. It is useful if you want to create the current time which will be stored in the database and want to compare it with something with what you store in the database. Otherwise, that you get back the one you store might be different, because the resolution of database timestamp is usually less than one millisecond, e.g., MS SQL: 0.003 second.
    If you don't cache it in the memory (remember entity beans always cache by the container), you don't need to round. If you are not sure, round it.
    
    See Also:
    
    round(Date, int)
  - now
```
public static final Date now()
```
    Returns the current time without rounding.
  - today
```
public static final Date today()
```
    Returns today by setting time to 0:0:0.
  - previousDate
```
public static final Date previousDate(Date when)
```
    Given a date, return the previous date of the given date (24 hrs before).
  - beginOfMonth
```
public static final Date beginOfMonth()
```
    Return the beginning date of this month.
  - beginOfMonth
```
public static final Date beginOfMonth(Date when,
                                      TimeZone tz)
```
    Given a date, a proper TimeZone, return the beginning date of the month of the specified date and TimeZone. If TimeZone is null, meaning use default TimeZone of the JVM.
  - endOfMonth
```
public static final Date endOfMonth()
```
    Return the ending date of this month.
  - endOfMonth
```
public static final Date endOfMonth(Date when,
                                    TimeZone tz)
```
    Given a date, a proper TimeZone, return the ending date of the month of the specified date and TimeZone. If TimeZone is null, meaning use default TimeZone of the JVM.
  - isEndOfMonth
```
public static final boolean isEndOfMonth(Date when,
                                         TimeZone tz)
```
    Whether the given date in the specified TimeZone is the last day of that month. If TimeZone is null, meaning use default TimeZone of the JVM.
  - isBeginOfMonth
```
public static final boolean isBeginOfMonth(Date when,
                                           TimeZone tz)
```
    Whether the given date in the specified TimeZone is the first day of that month. If TimeZone is null, meaning use default TimeZone of the JVM.
  - beginOfDate
```
public static final Date beginOfDate(Date when,
                                     TimeZone tz)
```
    Given a date, a proper TimeZone, return the beginning date of the specified date and TimeZone. If TimeZone is null, meaning use Default TimeZone of the JVM.
  - endOfDate
```
public static final Date endOfDate(Date when,
                                   TimeZone tz)
```
    Given a date, a proper TimeZone, return the last millisecond date of the specified date and TimeZone. If TimeZone is null, meaning use Default TimeZone of the JVM.
  - beginOfYear
```
public static final Date beginOfYear()
```
    Return the beginning date of this year.
  - beginOfYear
```
public static final Date beginOfYear(Date when,
                                     TimeZone tz)
```
    Given a date, a proper TimeZone, return the beginning date of the month of the specified date and TimeZone. If TimeZone is null, meaning use default TimeZone of the JVM.
  - endOfYear
```
public static final Date endOfYear()
```
    Return the ending date of this year.
  - endOfYear
```
public static final Date endOfYear(Date when,
                                   TimeZone tz)
```
    Given a date, a proper TimeZone, return the ending date of the month of the specified date and TimeZone. If TimeZone is null, meaning use default TimeZone of the JVM.
  - twoMonthShort
```
public static final short twoMonthShort()
```
    Return the ending date of this year.
  - twoMonthShort
```
public static final short twoMonthShort(Date when,
                                        TimeZone tz)
```
    Given a date, a proper TimeZone, return the two month int. e.g. 1, 3, 5, 7, 9, 11. If TimeZone is null, meaning use default TimeZone of the JVM.
  - yearOfDate
```
public static final int yearOfDate(Date when,
                                   TimeZone tz)
```
    Get the year of a date.
    
    Parameters:
    
    when - The date.
    
    tz - The time zone; if null, the current time zone is assumed.
    
    See Also:
    
    localizedYearOfDate(java.util.Date, java.util.Locale, java.util.TimeZone)
  - localizedYearOfDate
```
public static final int localizedYearOfDate(Date when,
                                            Locale locale,
                                            TimeZone tz)
```
    Get the year of a date in the specified locale.
    Currently, only Locale.ZH_TW is supported, i.e., "year - 1911" and it's may be less than 0. Otherwise, it is the same as yearOfDate(java.util.Date, java.util.TimeZone).
    
    Parameters:
    
    when - The date.
    
    locale - the locale; if null, the current locale is assumed.
    
    tz - The time zone; if null, the current time zone is assumed.
    
    See Also:
    
    yearOfDate(java.util.Date, java.util.TimeZone)
  - monthOfDate
```
public static final int monthOfDate(Date when,
                                    TimeZone tz)
```
    Get the month of a date. The first month of the year is JANUARY which is 0.
    
    Parameters:
    
    when - The date.
    
    tz - The time zone; if null, the current time zone is assumed.
  - monthOfDatePlus1
```
public static final int monthOfDatePlus1(Date when,
                                         TimeZone tz)
```
    Get the month of a date. The first month of the year is JANUARY which is 1.
    
    Parameters:
    
    when - The date.
    
    tz - The time zone; if null, the current time zone is assumed.
  - dayMonthOfDate
```
public static final int dayMonthOfDate(Date when,
                                       TimeZone tz)
```
    Get the day of month of a date. The first day of the month has value 1.
    
    Parameters:
    
    when - The date.
    
    tz - The time zone; if null, the current time zone is assumed.
  - add
```
public static final Date add(Date when,
                             TimeZone tz,
                             int field,
                             int amount)
```
    Date Arithmetic function. Adds the specified (signed) amount of time to the given date, based on the calendar's rules.
    
    Parameters:
    
    when - The based date.
    
    tz - The time zone; if null, the current time zone is assumed.
    
    field - The time field.
    
    amount - The amount of date or time to be added to the field.
  - subtract
```
public static final long subtract(Date date2,
                                  TimeZone tz,
                                  int field,
                                  Date date1)
```
    Date Arithmetic function (date2 - date1). subtract a date from another date, return the difference as the required fields. E.g. if specified Calendar.Date, the smaller range of fields is ignored and this method return the difference of days.
    
    Parameters:
    
    date2 - The date2.
    
    tz - The time zone.
    
    field - The time field; e.g., Calendar.DATE, Calendar.YEAR, it's default value is Calendar.DATE
    
    date1 - The date1.
  - merge
```
public static final Date merge(Date datePart,
                               Date timePart,
                               TimeZone tz)
```
    merge the date part and time part of two specified dates into a date.
    
    Parameters:
    
    datePart - The date part date.
    
    timePart - The time part date.
    
    tz - The time zone.
  - getTimezoneOffset
```
public static final long getTimezoneOffset(TimeZone timezone,
                                           Date date)
```
    Returns the timezone offset.
    
    Parameters:
    
    timezone - The time zone.
    
    date -
    
    Returns:
    
    long

Class Dates

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Dates

Method Detail

round

round

isRounded

now

now

today

previousDate

beginOfMonth

beginOfMonth

endOfMonth

endOfMonth

isEndOfMonth

isBeginOfMonth

beginOfDate

endOfDate

beginOfYear

beginOfYear

endOfYear

endOfYear

twoMonthShort

twoMonthShort

yearOfDate

localizedYearOfDate

monthOfDate

monthOfDatePlus1

dayMonthOfDate

add

subtract

merge

getTimezoneOffset