public
class
Date
extends Object
implements
Serializable,
Cloneable,
Comparable<Date>
java.lang.Object | |
↳ | java.util.Date |
Known Direct Subclasses |
The class Date
represents a specific instant
in time, with millisecond precision.
Prior to JDK 1.1, the class Date
had two additional
functions. It allowed the interpretation of dates as year, month, day, hour,
minute, and second values. It also allowed the formatting and parsing
of date strings. Unfortunately, the API for these functions was not
amenable to internationalization. As of JDK 1.1, the
Calendar
class should be used to convert between dates and time
fields and the DateFormat
class should be used to format and
parse date strings.
The corresponding methods in Date
are deprecated.
Although the Date
class is intended to reflect
coordinated universal time (UTC), it may not do so exactly,
depending on the host environment of the Java Virtual Machine.
Nearly all modern operating systems assume that 1 day =
24 × 60 × 60 = 86400 seconds
in all cases. In UTC, however, about once every year or two there
is an extra second, called a "leap second." The leap
second is always added as the last second of the day, and always
on December 31 or June 30. For example, the last minute of the
year 1995 was 61 seconds long, thanks to an added leap second.
Most computer clocks are not accurate enough to be able to reflect
the leap-second distinction.
Some computer standards are defined in terms of Greenwich mean time (GMT), which is equivalent to universal time (UT). GMT is the "civil" name for the standard; UT is the "scientific" name for the same standard. The distinction between UTC and UT is that UTC is based on an atomic clock and UT is based on astronomical observations, which for all practical purposes is an invisibly fine hair to split. Because the earth's rotation is not uniform (it slows down and speeds up in complicated ways), UT does not always flow uniformly. Leap seconds are introduced as needed into UTC so as to keep UTC within 0.9 seconds of UT1, which is a version of UT with certain corrections applied. There are other time and date systems as well; for example, the time scale used by the satellite-based global positioning system (GPS) is synchronized to UTC but is not adjusted for leap seconds. An interesting source of further information is the U.S. Naval Observatory, particularly the Directorate of Time at:
http://tycho.usno.navy.mil
and their definitions of "Systems of Time" at:
http://tycho.usno.navy.mil/systime.html
In all methods of class Date
that accept or return
year, month, date, hours, minutes, and seconds values, the
following representations are used:
- 1900
.
In all cases, arguments given to methods for these purposes need not fall within the indicated ranges; for example, a date may be specified as January 32 and is interpreted as meaning February 1.
See also:
Public constructors | |
---|---|
Date()
Allocates a |
|
Date(long date)
Allocates a |
|
Date(int year, int month, int date)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
|
Date(int year, int month, int date, int hrs, int min)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
|
Date(int year, int month, int date, int hrs, int min, int sec)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
|
Date(String s)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
Public methods | |
---|---|
static
long
|
UTC(int year, int month, int date, int hrs, int min, int sec)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
boolean
|
after(Date when)
Tests if this date is after the specified date. |
boolean
|
before(Date when)
Tests if this date is before the specified date. |
Object
|
clone()
Return a copy of this object. |
int
|
compareTo(Date anotherDate)
Compares two Dates for ordering. |
boolean
|
equals(Object obj)
Compares two dates for equality. |
int
|
getDate()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getDay()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getHours()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getMinutes()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getMonth()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getSeconds()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
long
|
getTime()
Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Date object. |
int
|
getTimezoneOffset()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
getYear()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
int
|
hashCode()
Returns a hash code value for this object. |
static
long
|
parse(String s)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setDate(int date)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setHours(int hours)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setMinutes(int minutes)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setMonth(int month)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setSeconds(int seconds)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
void
|
setTime(long time)
Sets this |
void
|
setYear(int year)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
String
|
toGMTString()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
String
|
toLocaleString()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by |
String
|
toString()
Converts this where:dow mon dd hh:mm:ss zzz yyyy
|
Inherited methods | |
---|---|
From
class
java.lang.Object
| |
From
interface
java.lang.Comparable
|
Date ()
Allocates a Date
object and initializes it so that
it represents the time at which it was allocated, measured to the
nearest millisecond.
See also:
Date (long date)
Allocates a Date
object and initializes it to
represent the specified number of milliseconds since the
standard base time known as "the epoch", namely January 1,
1970, 00:00:00 GMT.
Parameters | |
---|---|
date |
long :
the milliseconds since January 1, 1970, 00:00:00 GMT. |
See also:
Date (int year, int month, int date)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(year + 1900, month, date)
or GregorianCalendar(year + 1900, month, date)
.
Allocates a Date
object and initializes it so that
it represents midnight, local time, at the beginning of the day
specified by the year
, month
, and
date
arguments.
Parameters | |
---|---|
year |
int :
the year minus 1900. |
month |
int :
the month between 0-11. |
date |
int :
the day of the month between 1-31. |
See also:
Date (int year, int month, int date, int hrs, int min)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(year + 1900, month, date,
hrs, min)
or GregorianCalendar(year + 1900,
month, date, hrs, min)
.
Allocates a Date
object and initializes it so that
it represents the instant at the start of the minute specified by
the year
, month
, date
,
hrs
, and min
arguments, in the local
time zone.
Parameters | |
---|---|
year |
int :
the year minus 1900. |
month |
int :
the month between 0-11. |
date |
int :
the day of the month between 1-31. |
hrs |
int :
the hours between 0-23. |
min |
int :
the minutes between 0-59. |
See also:
Date (int year, int month, int date, int hrs, int min, int sec)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(year + 1900, month, date,
hrs, min, sec)
or GregorianCalendar(year + 1900,
month, date, hrs, min, sec)
.
Allocates a Date
object and initializes it so that
it represents the instant at the start of the second specified
by the year
, month
, date
,
hrs
, min
, and sec
arguments,
in the local time zone.
Parameters | |
---|---|
year |
int :
the year minus 1900. |
month |
int :
the month between 0-11. |
date |
int :
the day of the month between 1-31. |
hrs |
int :
the hours between 0-23. |
min |
int :
the minutes between 0-59. |
sec |
int :
the seconds between 0-59. |
See also:
Date (String s)
This constructor was deprecated
in API level 1.
As of JDK version 1.1,
replaced by DateFormat.parse(String s)
.
Allocates a Date
object and initializes it so that
it represents the date and time indicated by the string
s
, which is interpreted as if by the
parse(String)
method.
Parameters | |
---|---|
s |
String :
a string representation of the date. |
See also:
long UTC (int year, int month, int date, int hrs, int min, int sec)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(year + 1900, month, date,
hrs, min, sec)
or GregorianCalendar(year + 1900,
month, date, hrs, min, sec)
, using a UTC
TimeZone
, followed by Calendar.getTime().getTime()
.
Determines the date and time based on the arguments. The arguments are interpreted as a year, month, day of the month, hour of the day, minute within the hour, and second within the minute, exactly as for the Date constructor with six arguments, except that the arguments are interpreted relative to UTC rather than to the local time zone. The time indicated is returned represented as the distance, measured in milliseconds, of that time from the epoch (00:00:00 GMT on January 1, 1970).
Parameters | |
---|---|
year |
int :
the year minus 1900. |
month |
int :
the month between 0-11. |
date |
int :
the day of the month between 1-31. |
hrs |
int :
the hours between 0-23. |
min |
int :
the minutes between 0-59. |
sec |
int :
the seconds between 0-59. |
Returns | |
---|---|
long |
the number of milliseconds since January 1, 1970, 00:00:00 GMT for the date and time specified by the arguments. |
See also:
boolean after (Date when)
Tests if this date is after the specified date.
Parameters | |
---|---|
when |
Date :
a date. |
Returns | |
---|---|
boolean |
true if and only if the instant represented
by this Date object is strictly later than the
instant represented by when;
false otherwise. |
Throws | |
---|---|
NullPointerException |
if when is null.
|
boolean before (Date when)
Tests if this date is before the specified date.
Parameters | |
---|---|
when |
Date :
a date. |
Returns | |
---|---|
boolean |
true if and only if the instant of time
represented by this Date object is strictly
earlier than the instant represented by when;
false otherwise. |
Throws | |
---|---|
NullPointerException |
if when is null.
|
Object clone ()
Return a copy of this object.
Returns | |
---|---|
Object |
a clone of this instance. |
int compareTo (Date anotherDate)
Compares two Dates for ordering.
Parameters | |
---|---|
anotherDate |
Date :
the Date to be compared. |
Returns | |
---|---|
int |
the value 0 if the argument Date is equal to
this Date; a value less than 0 if this Date
is before the Date argument; and a value greater than
0 if this Date is after the Date argument. |
Throws | |
---|---|
NullPointerException |
if anotherDate is null.
|
boolean equals (Object obj)
Compares two dates for equality.
The result is true
if and only if the argument is
not null
and is a Date
object that
represents the same point in time, to the millisecond, as this object.
Thus, two Date
objects are equal if and only if the
getTime
method returns the same long
value for both.
Parameters | |
---|---|
obj |
Object :
the object to compare with. |
Returns | |
---|---|
boolean |
true if the objects are the same;
false otherwise. |
See also:
int getDate ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.DAY_OF_MONTH)
.
Returns the day of the month represented by this Date object.
The value returned is between 1
and 31
representing the day of the month that contains or begins with the
instant in time represented by this Date object, as
interpreted in the local time zone.
Returns | |
---|---|
int |
the day of the month represented by this date. |
See also:
int getDay ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.DAY_OF_WEEK)
.
Returns the day of the week represented by this date. The returned value (0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday, 6 = Saturday) represents the day of the week that contains or begins with the instant in time represented by this Date object, as interpreted in the local time zone.
Returns | |
---|---|
int |
the day of the week represented by this date. |
See also:
int getHours ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.HOUR_OF_DAY)
.
Returns the hour represented by this Date object. The returned value is a number (0 through 23) representing the hour within the day that contains or begins with the instant in time represented by this Date object, as interpreted in the local time zone.
Returns | |
---|---|
int |
the hour represented by this date. |
See also:
int getMinutes ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.MINUTE)
.
Returns the number of minutes past the hour represented by this date,
as interpreted in the local time zone.
The value returned is between 0
and 59
.
Returns | |
---|---|
int |
the number of minutes past the hour represented by this date. |
See also:
int getMonth ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.MONTH)
.
Returns a number representing the month that contains or begins
with the instant in time represented by this Date object.
The value returned is between 0
and 11
,
with the value 0
representing January.
Returns | |
---|---|
int |
the month represented by this date. |
See also:
int getSeconds ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.SECOND)
.
Returns the number of seconds past the minute represented by this date.
The value returned is between 0
and 61
. The
values 60
and 61
can only occur on those
Java Virtual Machines that take leap seconds into account.
Returns | |
---|---|
int |
the number of seconds past the minute represented by this date. |
See also:
long getTime ()
Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Date object.
Returns | |
---|---|
long |
the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this date. |
int getTimezoneOffset ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by -(Calendar.get(Calendar.ZONE_OFFSET) +
Calendar.get(Calendar.DST_OFFSET)) / (60 * 1000)
.
Returns the offset, measured in minutes, for the local time zone
relative to UTC that is appropriate for the time represented by
this Date
object.
For example, in Massachusetts, five time zones west of Greenwich:
because on February 14, 1996, standard time (Eastern Standard Time) is in use, which is offset five hours from UTC; but:new Date(96, 1, 14).getTimezoneOffset() returns 300
because on June 1, 1996, daylight saving time (Eastern Daylight Time) is in use, which is offset only four hours from UTC.new Date(96, 5, 1).getTimezoneOffset() returns 240
This method produces the same result as if it computed:
(this.getTime() - UTC(this.getYear(), this.getMonth(), this.getDate(), this.getHours(), this.getMinutes(), this.getSeconds())) / (60 * 1000)
Returns | |
---|---|
int |
the time-zone offset, in minutes, for the current time zone. |
See also:
int getYear ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.get(Calendar.YEAR) - 1900
.
Returns a value that is the result of subtracting 1900 from the
year that contains or begins with the instant in time represented
by this Date
object, as interpreted in the local
time zone.
Returns | |
---|---|
int |
the year represented by this date, minus 1900. |
See also:
int hashCode ()
Returns a hash code value for this object. The result is the
exclusive OR of the two halves of the primitive long
value returned by the getTime()
method. That is, the hash code is the value of the expression:
(int)(this.getTime()^(this.getTime() >>> 32))
Returns | |
---|---|
int |
a hash code value for this object. |
long parse (String s)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by DateFormat.parse(String s)
.
Attempts to interpret the string s as a representation of a date and time. If the attempt is successful, the time indicated is returned represented as the distance, measured in milliseconds, of that time from the epoch (00:00:00 GMT on January 1, 1970). If the attempt fails, an IllegalArgumentException is thrown.
It accepts many syntaxes; in particular, it recognizes the IETF standard date syntax: "Sat, 12 Aug 1995 13:30:00 GMT". It also understands the continental U.S. time-zone abbreviations, but for general use, a time-zone offset should be used: "Sat, 12 Aug 1995 13:30:00 GMT+0430" (4 hours, 30 minutes west of the Greenwich meridian). If no time zone is specified, the local time zone is assumed. GMT and UTC are considered equivalent.
The string s is processed from left to right, looking for data of interest. Any material in s that is within the ASCII parenthesis characters ( and ) is ignored. Parentheses may be nested. Otherwise, the only characters permitted within s are these ASCII characters:
and whitespace characters.abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789,+-:/
A consecutive sequence of decimal digits is treated as a decimal number:
SimpleDateFormat
.
A consecutive sequence of letters is regarded as a word and treated as follows:
Once the entire string s has been scanned, it is converted to a time result in one of two ways. If a time zone or time-zone offset has been recognized, then the year, month, day of month, hour, minute, and second are interpreted in UTC and then the time-zone offset is applied. Otherwise, the year, month, day of month, hour, minute, and second are interpreted in the local time zone.
Parameters | |
---|---|
s |
String :
a string to be parsed as a date. |
Returns | |
---|---|
long |
the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by the string argument. |
See also:
void setDate (int date)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.DAY_OF_MONTH, int date)
.
Sets the day of the month of this Date object to the specified value. This Date object is modified so that it represents a point in time within the specified day of the month, with the year, month, hour, minute, and second the same as before, as interpreted in the local time zone. If the date was April 30, for example, and the date is set to 31, then it will be treated as if it were on May 1, because April has only 30 days.
Parameters | |
---|---|
date |
int :
the day of the month value between 1-31. |
See also:
void setHours (int hours)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.HOUR_OF_DAY, int hours)
.
Sets the hour of this Date object to the specified value. This Date object is modified so that it represents a point in time within the specified hour of the day, with the year, month, date, minute, and second the same as before, as interpreted in the local time zone.
Parameters | |
---|---|
hours |
int :
the hour value. |
See also:
void setMinutes (int minutes)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.MINUTE, int minutes)
.
Sets the minutes of this Date object to the specified value. This Date object is modified so that it represents a point in time within the specified minute of the hour, with the year, month, date, hour, and second the same as before, as interpreted in the local time zone.
Parameters | |
---|---|
minutes |
int :
the value of the minutes. |
See also:
void setMonth (int month)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.MONTH, int month)
.
Sets the month of this date to the specified value. This Date object is modified so that it represents a point in time within the specified month, with the year, date, hour, minute, and second the same as before, as interpreted in the local time zone. If the date was October 31, for example, and the month is set to June, then the new date will be treated as if it were on July 1, because June has only 30 days.
Parameters | |
---|---|
month |
int :
the month value between 0-11. |
See also:
void setSeconds (int seconds)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.SECOND, int seconds)
.
Sets the seconds of this Date to the specified value. This Date object is modified so that it represents a point in time within the specified second of the minute, with the year, month, date, hour, and minute the same as before, as interpreted in the local time zone.
Parameters | |
---|---|
seconds |
int :
the seconds value. |
See also:
void setTime (long time)
Sets this Date
object to represent a point in time that is
time
milliseconds after January 1, 1970 00:00:00 GMT.
Parameters | |
---|---|
time |
long :
the number of milliseconds.
|
void setYear (int year)
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by Calendar.set(Calendar.YEAR, year + 1900)
.
Sets the year of this Date object to be the specified
value plus 1900. This Date
object is modified so
that it represents a point in time within the specified year,
with the month, date, hour, minute, and second the same as
before, as interpreted in the local time zone. (Of course, if
the date was February 29, for example, and the year is set to a
non-leap year, then the new date will be treated as if it were
on March 1.)
Parameters | |
---|---|
year |
int :
the year value. |
See also:
String toGMTString ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by DateFormat.format(Date date)
, using a
GMT TimeZone
.
Creates a string representation of this Date object of the form:
d mon yyyy hh:mm:ss GMTwhere:
The result does not depend on the local time zone.
Returns | |
---|---|
String |
a string representation of this date, using the Internet GMT conventions. |
See also:
String toLocaleString ()
This method was deprecated
in API level 1.
As of JDK version 1.1,
replaced by DateFormat.format(Date date)
.
Creates a string representation of this Date object in an
implementation-dependent form. The intent is that the form should
be familiar to the user of the Java application, wherever it may
happen to be running. The intent is comparable to that of the
"%c
" format supported by the strftime()
function of ISO C.
Returns | |
---|---|
String |
a string representation of this date, using the locale conventions. |
See also:
String toString ()
Converts this Date
object to a String
of the form:
where:dow mon dd hh:mm:ss zzz yyyy
Returns | |
---|---|
String |
a string representation of this date. |
See also: