org.apache.commons.lang.time

Class DateUtils


public class DateUtils
extends Object

A suite of utilities surrounding the use of the Calendar and Date object.
Version:
$Id: DateUtils.java 161243 2005-04-14 04:30:28Z ggregory $
Authors:
Serge Knystautas
Stephen Colebourne
Janek Bogucki
Gary Gregory
Phil Steitz
Since:
2.0

Field Summary

static int
MILLIS_IN_DAY
Deprecated. Use MILLIS_PER_DAY.
static int
MILLIS_IN_HOUR
Deprecated. Use MILLIS_PER_HOUR.
static int
MILLIS_IN_MINUTE
Deprecated. Use MILLIS_PER_MINUTE.
static int
MILLIS_IN_SECOND
Deprecated. Use MILLIS_PER_SECOND.
static long
MILLIS_PER_DAY
Number of milliseconds in a standard day.
static long
MILLIS_PER_HOUR
Number of milliseconds in a standard hour.
static long
MILLIS_PER_MINUTE
Number of milliseconds in a standard minute.
static long
MILLIS_PER_SECOND
Number of milliseconds in a standard second.
static int
RANGE_MONTH_MONDAY
A month range, the week starting on Monday.
static int
RANGE_MONTH_SUNDAY
A month range, the week starting on Sunday.
static int
RANGE_WEEK_CENTER
A week range, centered around the day focused.
static int
RANGE_WEEK_MONDAY
A week range, starting on Monday.
static int
RANGE_WEEK_RELATIVE
A week range, starting on the day focused.
static int
RANGE_WEEK_SUNDAY
A week range, starting on Sunday.
static int
SEMI_MONTH
This is half a month, so this represents whether a date is in the top or bottom half of the month.
static TimeZone
UTC_TIME_ZONE
The UTC time zone (often referred to as GMT).

Constructor Summary

DateUtils()
DateUtils instances should NOT be constructed in standard programming.

Method Summary

static boolean
isSameDay(Calendar cal1, Calendar cal2)
Checks if two calendar objects are on the same day ignoring time.
static boolean
isSameDay(Date date1, Date date2)
Checks if two date objects are on the same day ignoring time.
static boolean
isSameInstant(Calendar cal1, Calendar cal2)
Checks if two calendar objects represent the same instant in time.
static boolean
isSameInstant(Date date1, Date date2)
Checks if two date objects represent the same instant in time.
static boolean
isSameLocalTime(Calendar cal1, Calendar cal2)
Checks if two calendar objects represent the same local time.
static Iterator
iterator(Calendar focus, int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.
static Iterator
iterator(Date focus, int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.
static Iterator
iterator(Object focus, int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.
static Date
parseDate(String str, String[] parsePatterns)
Parses a string representing a date by trying a variety of different parsers.
static Calendar
round(Calendar date, int field)
Round this date, leaving the field specified as the most significant field.
static Date
round(Date date, int field)
Round this date, leaving the field specified as the most significant field.
static Date
round(Object date, int field)
Round this date, leaving the field specified as the most significant field.
static Calendar
truncate(Calendar date, int field)
Truncate this date, leaving the field specified as the most significant field.
static Date
truncate(Date date, int field)
Truncate this date, leaving the field specified as the most significant field.
static Date
truncate(Object date, int field)
Truncate this date, leaving the field specified as the most significant field.

Field Details

MILLIS_IN_DAY

public static final int MILLIS_IN_DAY

Deprecated. Use MILLIS_PER_DAY. This will be removed in Commons Lang 3.0.

Number of milliseconds in a standard day.
Field Value:
86400000

MILLIS_IN_HOUR

public static final int MILLIS_IN_HOUR

Deprecated. Use MILLIS_PER_HOUR. This will be removed in Commons Lang 3.0.

Number of milliseconds in a standard hour.
Field Value:
3600000

MILLIS_IN_MINUTE

public static final int MILLIS_IN_MINUTE

Deprecated. Use MILLIS_PER_MINUTE. This will be removed in Commons Lang 3.0.

Number of milliseconds in a standard minute.
Field Value:
60000

MILLIS_IN_SECOND

public static final int MILLIS_IN_SECOND

Deprecated. Use MILLIS_PER_SECOND. This will be removed in Commons Lang 3.0.

Number of milliseconds in a standard second.
Field Value:
1000

MILLIS_PER_DAY

public static final long MILLIS_PER_DAY
Number of milliseconds in a standard day.
Field Value:
86400000L
Since:
2.1

MILLIS_PER_HOUR

public static final long MILLIS_PER_HOUR
Number of milliseconds in a standard hour.
Field Value:
3600000L
Since:
2.1

MILLIS_PER_MINUTE

public static final long MILLIS_PER_MINUTE
Number of milliseconds in a standard minute.
Field Value:
60000L
Since:
2.1

MILLIS_PER_SECOND

public static final long MILLIS_PER_SECOND
Number of milliseconds in a standard second.
Field Value:
1000L
Since:
2.1

RANGE_MONTH_MONDAY

public static final int RANGE_MONTH_MONDAY
A month range, the week starting on Monday.
Field Value:
6

RANGE_MONTH_SUNDAY

public static final int RANGE_MONTH_SUNDAY
A month range, the week starting on Sunday.
Field Value:
5

RANGE_WEEK_CENTER

public static final int RANGE_WEEK_CENTER
A week range, centered around the day focused.
Field Value:
4

RANGE_WEEK_MONDAY

public static final int RANGE_WEEK_MONDAY
A week range, starting on Monday.
Field Value:
2

RANGE_WEEK_RELATIVE

public static final int RANGE_WEEK_RELATIVE
A week range, starting on the day focused.
Field Value:
3

RANGE_WEEK_SUNDAY

public static final int RANGE_WEEK_SUNDAY
A week range, starting on Sunday.
Field Value:
1

SEMI_MONTH

public static final int SEMI_MONTH
This is half a month, so this represents whether a date is in the top or bottom half of the month.
Field Value:
1001

UTC_TIME_ZONE

public static final TimeZone UTC_TIME_ZONE
The UTC time zone (often referred to as GMT).

Constructor Details

DateUtils

public DateUtils()
DateUtils instances should NOT be constructed in standard programming. Instead, the class should be used as DateUtils.parse(str);.

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Details

isSameDay

public static boolean isSameDay(Calendar cal1,
                                Calendar cal2)
Checks if two calendar objects are on the same day ignoring time.

28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true. 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.

Parameters:
cal1 - the first calendar, not altered, not null
cal2 - the second calendar, not altered, not null
Returns:
true if they represent the same day
Since:
2.1

isSameDay

public static boolean isSameDay(Date date1,
                                Date date2)
Checks if two date objects are on the same day ignoring time.

28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true. 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.

Parameters:
date1 - the first date, not altered, not null
date2 - the second date, not altered, not null
Returns:
true if they represent the same day
Since:
2.1

isSameInstant

public static boolean isSameInstant(Calendar cal1,
                                    Calendar cal2)
Checks if two calendar objects represent the same instant in time.

This method compares the long millisecond time of the two objects.

Parameters:
cal1 - the first calendar, not altered, not null
cal2 - the second calendar, not altered, not null
Returns:
true if they represent the same millisecond instant
Since:
2.1

isSameInstant

public static boolean isSameInstant(Date date1,
                                    Date date2)
Checks if two date objects represent the same instant in time.

This method compares the long millisecond time of the two objects.

Parameters:
date1 - the first date, not altered, not null
date2 - the second date, not altered, not null
Returns:
true if they represent the same millisecond instant
Since:
2.1

isSameLocalTime

public static boolean isSameLocalTime(Calendar cal1,
                                      Calendar cal2)
Checks if two calendar objects represent the same local time.

This method compares the values of the fields of the two objects. In addition, both calendars must be the same of the same type.

Parameters:
cal1 - the first calendar, not altered, not null
cal2 - the second calendar, not altered, not null
Returns:
true if they represent the same millisecond instant
Since:
2.1

iterator

public static Iterator iterator(Calendar focus,
                                int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.

For instance, passing Thursday, July 4, 2002 and a RANGE_MONTH_SUNDAY will return an Iterator that starts with Sunday, June 30, 2002 and ends with Saturday, August 3, 2002.

Returns:
the date iterator

iterator

public static Iterator iterator(Date focus,
                                int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.

For instance, passing Thursday, July 4, 2002 and a RANGE_MONTH_SUNDAY will return an Iterator that starts with Sunday, June 30, 2002 and ends with Saturday, August 3, 2002.

Returns:
the date iterator

iterator

public static Iterator iterator(Object focus,
                                int rangeStyle)
This constructs an Iterator that will start and stop over a date range based on the focused date and the range style.

For instance, passing Thursday, July 4, 2002 and a RANGE_MONTH_SUNDAY will return an Iterator that starts with Sunday, June 30, 2002 and ends with Saturday, August 3, 2002.

Returns:
the date iterator

parseDate

public static Date parseDate(String str,
                             String[] parsePatterns)
            throws ParseException
Parses a string representing a date by trying a variety of different parsers.

The parse will try each parse pattern in turn. A parse is only deemed sucessful if it parses the whole of the input string. If no parse patterns match, a ParseException is thrown.

Parameters:
str - the date to parse, not null
parsePatterns - the date format patterns to use, see SimpleDateFormat, not null
Returns:
the parsed date

round

public static Calendar round(Calendar date,
                             int field)
Round this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if this was passed with HOUR, it would return 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it would return 1 April 2002 0:00:00.000.

For a date in a timezone that handles the change to daylight saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows. Suppose daylight saving time begins at 02:00 on March 30. Rounding a date that crosses this time would produce the following values:

  • March 30, 2003 01:10 rounds to March 30, 2003 01:00
  • March 30, 2003 01:40 rounds to March 30, 2003 03:00
  • March 30, 2003 02:10 rounds to March 30, 2003 03:00
  • March 30, 2003 02:40 rounds to March 30, 2003 04:00
Parameters:
date - the date to work with
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date (a different object)

round

public static Date round(Date date,
                         int field)
Round this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if this was passed with HOUR, it would return 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it would return 1 April 2002 0:00:00.000.

For a date in a timezone that handles the change to daylight saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows. Suppose daylight saving time begins at 02:00 on March 30. Rounding a date that crosses this time would produce the following values:

  • March 30, 2003 01:10 rounds to March 30, 2003 01:00
  • March 30, 2003 01:40 rounds to March 30, 2003 03:00
  • March 30, 2003 02:10 rounds to March 30, 2003 03:00
  • March 30, 2003 02:40 rounds to March 30, 2003 04:00
Parameters:
date - the date to work with
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date

round

public static Date round(Object date,
                         int field)
Round this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if this was passed with HOUR, it would return 28 Mar 2002 14:00:00.000. If this was passed with MONTH, it would return 1 April 2002 0:00:00.000.

For a date in a timezone that handles the change to daylight saving time, rounding to Calendar.HOUR_OF_DAY will behave as follows. Suppose daylight saving time begins at 02:00 on March 30. Rounding a date that crosses this time would produce the following values:

  • March 30, 2003 01:10 rounds to March 30, 2003 01:00
  • March 30, 2003 01:40 rounds to March 30, 2003 03:00
  • March 30, 2003 02:10 rounds to March 30, 2003 03:00
  • March 30, 2003 02:40 rounds to March 30, 2003 04:00
Parameters:
date - the date to work with, either Date or Calendar
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date

truncate

public static Calendar truncate(Calendar date,
                                int field)
Truncate this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if you passed with HOUR, it would return 28 Mar 2002 13:00:00.000. If this was passed with MONTH, it would return 1 Mar 2002 0:00:00.000.

Parameters:
date - the date to work with
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date (a different object)

truncate

public static Date truncate(Date date,
                            int field)
Truncate this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if you passed with HOUR, it would return 28 Mar 2002 13:00:00.000. If this was passed with MONTH, it would return 1 Mar 2002 0:00:00.000.

Parameters:
date - the date to work with
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date

truncate

public static Date truncate(Object date,
                            int field)
Truncate this date, leaving the field specified as the most significant field.

For example, if you had the datetime of 28 Mar 2002 13:45:01.231, if you passed with HOUR, it would return 28 Mar 2002 13:00:00.000. If this was passed with MONTH, it would return 1 Mar 2002 0:00:00.000.

Parameters:
date - the date to work with, either Date or Calendar
field - the field from Calendar or SEMI_MONTH
Returns:
the rounded date

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