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Core JavaScript Reference 1.5





Date

Lets you work with dates and times.


Core object

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.1: added prototype property.

JavaScript 1.3: removed platform dependencies to provide a uniform behavior across platforms; added ms_num parameter to Date constructor; added getFullYear, setFullYear, getMilliseconds, setMilliseconds, toSource, and UTC methods (such as getUTCDate and setUTCDate).  

ECMA version  

ECMA-262  


Created by
The Date constructor:

new Date()
new Date(milliseconds)
new Date(dateString)
new Date(yr_num, mo_num, day_num
        [, hr_num, min_num, sec_num, ms_num])

Versions prior to JavaScript 1.3:

new Date()
new Date(milliseconds)
new Date(dateString)
new Date(yr_num, mo_num, day_num[, hr_num, min_num, sec_num])


Parameters


milliseconds

 

Integer value representing the number of milliseconds since 1 January 1970 00:00:00.  

dateString

 

String value representing a date. The string should be in a format recognized by the Date.parse method.  

yr_num, mo_num,
day_num

 

Integer values representing part of a date. As an integer value, the month is represented by 0 to 11 with 0=January and 11=December.  

hr_num, min_num,
sec_num, ms_num

 

Integer values representing part of a date.  


Description
If you supply no arguments, the constructor creates a Date object for today's date and time according to local time. If you supply some arguments but not others, the missing arguments are set to 0. If you supply any arguments, you must supply at least the year, month, and day. You can omit the hours, minutes, seconds, and milliseconds.

The date is measured in milliseconds since midnight 01 January, 1970 UTC. A day holds 86,400,000 milliseconds. The Date object range is -100,000,000 days to 100,000,000 days relative to 01 January, 1970 UTC.

The Date object provides uniform behavior across platforms.

The Date object supports a number of UTC (universal) methods, as well as local time methods. UTC, also known as Greenwich Mean Time (GMT), refers to the time as set by the World Time Standard. The local time is the time known to the computer where JavaScript is executed.

For compatibility with millennium calculations (in other words, to take into account the year 2000), you should always specify the year in full; for example, use 1998, not 98. To assist you in specifying the complete year, JavaScript includes the methods getFullYear, setFullYear, getFullUTCYear, and setFullUTCYear.

The following example returns the time elapsed between timeA and timeB in milliseconds.

timeA = new Date();
// Statements here to take some action.
timeB = new Date();
timeDifference = timeB - timeA;


Backward Compatibility

JavaScript 1.2 and earlier. The Date object behaves as follows:


Property Summary



Property

Description

constructor

 

Specifies the function that creates an object's prototype.  

prototype

 

Allows the addition of properties to a Date object.  


Method Summary



Method

Description

getDate

 

Returns the day of the month for the specified date according to local time.  

getDay

 

Returns the day of the week for the specified date according to local time.  

getFullYear  

Returns the year of the specified date according to local time.  

getHours

 

Returns the hour in the specified date according to local time.  

getMilliseconds  

Returns the milliseconds in the specified date according to local time.  

getMinutes

 

Returns the minutes in the specified date according to local time.  

getMonth

 

Returns the month in the specified date according to local time.  

getSeconds

 

Returns the seconds in the specified date according to local time.  

getTime

 

Returns the numeric value corresponding to the time for the specified date according to local time.  

getTimezoneOffset

 

Returns the time-zone offset in minutes for the current locale.  

getUTCDate  

Returns the day (date) of the month in the specified date according to universal time.  

getUTCDay  

Returns the day of the week in the specified date according to universal time.  

getUTCFullYear  

Returns the year in the specified date according to universal time.  

getUTCHours  

Returns the hours in the specified date according to universal time.  

getUTCMilliseconds  

Returns the milliseconds in the specified date according to universal time.  

getUTCMinutes  

Returns the minutes in the specified date according to universal time.  

getUTCMonth  

Returns the month according in the specified date according to universal time.  

getUTCSeconds  

Returns the seconds in the specified date according to universal time.  

getYear

 

Returns the year in the specified date according to local time.  

parse

 

Returns the number of milliseconds in a date string since January 1, 1970, 00:00:00, local time.  

setDate

 

Sets the day of the month for a specified date according to local time.  

setFullYear  

Sets the full year for a specified date according to local time.  

setHours

 

Sets the hours for a specified date according to local time.  

setMilliseconds  

Sets the milliseconds for a specified date according to local time.  

setMinutes

 

Sets the minutes for a specified date according to local time.  

setMonth

 

Sets the month for a specified date according to local time.  

setSeconds  

Sets the seconds for a specified date according to local time.  

setTime  

Sets the value of a Date object according to local time.  

setUTCDate  

Sets the day of the month for a specified date according to universal time.  

setUTCFullYear  

Sets the full year for a specified date according to universal time.  

setUTCHours  

Sets the hour for a specified date according to universal time.  

setUTCMilliseconds  

Sets the milliseconds for a specified date according to universal time.  

setUTCMinutes  

Sets the minutes for a specified date according to universal time.  

setUTCMonth  

Sets the month for a specified date according to universal time.  

setUTCSeconds  

Sets the seconds for a specified date according to universal time.  

setYear

 

Sets the year for a specified date according to local time.  

toGMTString

 

Converts a date to a string, using the Internet GMT conventions.  

toLocaleString

 

Converts a date to a string, using the current locale's conventions.  

toSource

 

Returns an object literal representing the specified Date object; you can use this value to create a new object. Overrides the Object.toSource method.  

toString

 

Returns a string representing the specified Date object. Overrides the Object.toString method.  

toUTCString  

Converts a date to a string, using the universal time convention.  

UTC

 

Returns the number of milliseconds in a Date object since January 1, 1970, 00:00:00, universal time.  

valueOf

 

Returns the primitive value of a Date object. Overrides the Object.valueOf method.  

In addition, this object inherits the watch and unwatch methods from Object.


Examples
The following examples show several ways to assign dates:

today = new Date()
birthday = new Date("December 17, 1995 03:24:00")
birthday = new Date(95,11,17)
birthday = new Date(95,11,17,3,24,0)


constructor

Specifies the function that creates an object's prototype. Note that the value of this property is a reference to the function itself, not a string containing the function's name.



Property of  

Date  

Implemented in  

JavaScript 1.1, NES 2.0  

ECMA version  

ECMA-262  


Description
See Object.constructor.


getDate

Returns the day of the month for the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getDate()


Parameters
None


Description
The value returned by getDate is an integer between 1 and 31.


Examples
The second statement below assigns the value 25 to the variable day, based on the value of the Date object Xmas95.

Xmas95 = new Date("December 25, 1995 23:15:00")
day = Xmas95.getDate()


See also
Date.getUTCDate, Date.getUTCDay, Date.setDate


getDay

Returns the day of the week for the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getDay()


Parameters
None


Description
The value returned by getDay is an integer corresponding to the day of the week: 0 for Sunday, 1 for Monday, 2 for Tuesday, and so on.


Examples
The second statement below assigns the value 1 to weekday, based on the value of the Date object Xmas95. December 25, 1995, is a Monday.

Xmas95 = new Date("December 25, 1995 23:15:00")
weekday = Xmas95.getDay()


See also
Date.getUTCDay, Date.setDate


getFullYear

Returns the year of the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getFullYear()


Parameters
None


Description
The value returned by getFullYear is an absolute number. For dates between the years 1000 and 9999, getFullYear returns a four-digit number, for example, 1995. Use this function to make sure a year is compliant with years after 2000.

Use this method instead of the getYear method.


Examples
The following example assigns the four-digit value of the current year to the variable yr.

var yr;
Today = new Date();
yr = Today.getFullYear();


See also
Date.getYear, Date.getUTCFullYear , Date.setFullYear


getHours

Returns the hour for the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getHours()


Parameters
None


Description
The value returned by getHours is an integer between 0 and 23.


Examples
The second statement below assigns the value 23 to the variable hours, based on the value of the Date object Xmas95.

Xmas95 = new Date("December 25, 1995 23:15:00")
hours = Xmas95.getHours()


See also
Date.getUTCHours, Date.setHours


getMilliseconds

Returns the milliseconds in the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getMilliseconds()


Parameters
None


Description
The value returned by getMilliseconds is a number between 0 and 999.


Examples
The following example assigns the milliseconds portion of the current time to the variable ms.

var ms;
Today = new Date();
ms = Today.getMilliseconds();


See also
Date.getUTCMilliseconds , Date.setMilliseconds


getMinutes

Returns the minutes in the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getMinutes()


Parameters
None


Description
The value returned by getMinutes is an integer between 0 and 59.


Examples
The second statement below assigns the value 15 to the variable minutes, based on the value of the Date object Xmas95.

Xmas95 = new Date("December 25, 1995 23:15:00")
minutes = Xmas95.getMinutes()


See also
Date.getUTCMinutes, Date.setMinutes


getMonth

Returns the month in the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getMonth()


Parameters
None


Description
The value returned by getMonth is an integer between 0 and 11. 0 corresponds to January, 1 to February, and so on.


Examples
The second statement below assigns the value 11 to the variable month, based on the value of the Date object Xmas95.

Xmas95 = new Date("December 25, 1995 23:15:00")
month = Xmas95.getMonth()


See also
Date.getUTCMonth, Date.setMonth


getSeconds

Returns the seconds in the current time according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getSeconds()


Parameters
None


Description
The value returned by getSeconds is an integer between 0 and 59.


Examples
The second statement below assigns the value 30 to the variable secs, based on the value of the Date object Xmas95.

Xmas95 = new Date("December 25, 1995 23:15:30")
secs = Xmas95.getSeconds()


See also
Date.getUTCSeconds, Date.setSeconds


getTime

Returns the numeric value corresponding to the time for the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getTime()


Parameters
None


Description
The value returned by the getTime method is the number of milliseconds since 1 January 1970 00:00:00. You can use this method to help assign a date and time to another Date object.


Examples
The following example assigns the date value of theBigDay to sameAsBigDay:

theBigDay = new Date("July 1, 1999")
sameAsBigDay = new Date()
sameAsBigDay.setTime(theBigDay.getTime())


See also
Date.getUTCHours, Date.setTime


getTimezoneOffset

Returns the time-zone offset in minutes for the current locale.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
getTimezoneOffset()


Parameters
None


Description
The time-zone offset is the difference between local time and Greenwich Mean Time (GMT). Daylight savings time prevents this value from being a constant.


Examples
x = new Date()
currentTimeZoneOffsetInHours = x.getTimezoneOffset()/60


getUTCDate

Returns the day (date) of the month in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCDate()


Parameters
None


Description
The value returned by getUTCDate is an integer between 1 and 31.


Examples
The following example assigns the day portion of the current date to the variable d.

var d;
Today = new Date();
d = Today.getUTCDate();


See also
Date.getDate , Date.getUTCDay , Date.setUTCDate


getUTCDay

Returns the day of the week in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCDay()


Parameters
None


Description
The value returned by getUTCDay is an integer corresponding to the day of the week: 0 for Sunday, 1 for Monday, 2 for Tuesday, and so on.


Examples
The following example assigns the weekday portion of the current date to the variable ms.

var weekday;
Today = new Date()
weekday = Today.getUTCDay()


See also
Date.getDay , Date.getUTCDate , Date.setUTCDate


getUTCFullYear

Returns the year in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCFullYear()


Parameters
None


Description
The value returned by getUTCFullYear is an absolute number that is compliant with year-2000, for example, 1995.


Examples
The following example assigns the four-digit value of the current year to the variable yr.

var yr;
Today = new Date();
yr = Today.getUTCFullYear();


See also
Date.getFullYear , Date.setFullYear


getUTCHours

Returns the hours in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCHours()


Parameters
None


Description
The value returned by getUTCHours is an integer between 0 and 23.


Examples
The following example assigns the hours portion of the current time to the variable hrs.

var hrs;
Today = new Date();
hrs = Today.getUTCHours();


See also
Date.getHours , Date.setUTCHours


getUTCMilliseconds

Returns the milliseconds in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCMilliSeconds()


Parameters
None


Description
The value returned by getUTCMilliseconds is an integer between 0 and 999.


Examples
The following example assigns the milliseconds portion of the current time to the variable ms.

var ms;
Today = new Date();
ms = Today.getUTCMilliseconds();


See also
Date.getMilliseconds , Date.setUTCMilliseconds


getUTCMinutes

Returns the minutes in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCMinutes()


Parameters
None


Description
The value returned by getUTCMinutes is an integer between 0 and 59.


Examples
The following example assigns the minutes portion of the current time to the variable min.

var min;
Today = new Date();
min = Today.getUTCMinutes();


See also
Date.getMinutes , Date.setUTCMinutes


getUTCMonth

Returns the month according in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCMonth()


Parameters
None


Description
The value returned by getUTCMonth is an integer between 0 and 11 corresponding to the month. 0 for January, 1 for February, 2 for March, and so on.


Examples
The following example assigns the month portion of the current date to the variable mon.

var mon;
Today = new Date();
mon = Today.getUTCMonth();


See also
Date.getMonth , Date.setUTCMonth


getUTCSeconds

Returns the seconds in the specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
getUTCSeconds()


Parameters
None


Description
The value returned by getUTCSeconds is an integer between 0 and 59.


Examples
The following example assigns the seconds portion of the current time to the variable sec.

var sec;
Today = new Date();
sec = Today.getUTCSeconds();


See also
Date.getSeconds , Date.setUTCSeconds


getYear

Returns the year in the specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: deprecated; also, getYear returns the year minus 1900 regardless of the year specified  

ECMA version  

ECMA-262  


Syntax
getYear()


Parameters
None


Description
getYear is no longer used and has been replaced by the getFullYear method.

The getYear method returns the year minus 1900; thus:

To take into account years before and after 2000, you should use Date.getFullYear instead of getYear so that the year is specified in full.


Backward Compatibility

JavaScript 1.2 and earlier versions. The getYear method returns either a 2-digit or 4-digit year:


Examples
Example 1. The second statement assigns the value 95 to the variable year.

Xmas = new Date("December 25, 1995 23:15:00")
year = Xmas.getYear() // returns 95

Example 2. The second statement assigns the value 100 to the variable year.

Xmas = new Date("December 25, 2000 23:15:00")
year = Xmas.getYear() // returns 100

Example 3. The second statement assigns the value -100 to the variable year.

Xmas = new Date("December 25, 1800 23:15:00")
year = Xmas.getYear() // returns -100

Example 4. The second statement assigns the value 95 to the variable year, representing the year 1995.

Xmas.setYear(95)
year = Xmas.getYear() // returns 95


See also
Date.getFullYear, Date.getUTCFullYear, Date.setYear


parse

Returns the number of milliseconds in a date string since January 1, 1970, 00:00:00, local time.



Method of  

Date  

Static

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
Date.parse(dateString)


Parameters
:



dateString

 

A string representing a date.  


Description
The parse method takes a date string (such as "Dec 25, 1995") and returns the number of milliseconds since January 1, 1970, 00:00:00 (local time). This function is useful for setting date values based on string values, for example in conjunction with the setTime method and the Date object.

Given a string representing a time, parse returns the time value. It accepts the IETF standard date syntax: "Mon, 25 Dec 1995 13:30:00 GMT". It understands the continental US time-zone abbreviations, but for general use, use a time-zone offset, for example, "Mon, 25 Dec 1995 13:30:00 GMT+0430" (4 hours, 30 minutes west of the Greenwich meridian). If you do not specify a time zone, the local time zone is assumed. GMT and UTC are considered equivalent.

Because parse is a static method of Date, you always use it as Date.parse(), rather than as a method of a Date object you created.


Examples
If IPOdate is an existing Date object, then you can set it to August 9, 1995 as follows:

IPOdate.setTime(Date.parse("Aug 9, 1995"))


See also
Date.UTC


prototype

Represents the prototype for this class. You can use the prototype to add properties or methods to all instances of a class. For information on prototypes, see Function.prototype.



Property of  

Date  

Implemented in  

JavaScript 1.1, NES 2.0  

ECMA version  

ECMA-262  


setDate

Sets the day of the month for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
setDate(dayValue)


Parameters



dayValue

 

An integer from 1 to 31, representing the day of the month.  


Examples
The second statement below changes the day for theBigDay to July 24 from its original value.

theBigDay = new Date("July 27, 1962 23:30:00")
theBigDay.setDate(24)


See also
Date.getDate, Date.setUTCDate


setFullYear

Sets the full year for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setFullYear(yearValue[, monthValue, dayValue])


Parameters



yearValue

 

An integer specifying the numeric value of the year, for example, 1995.  

monthValue

 

An integer between 0 and 11 representing the months January through December.  

dayValue

 

An integer between 1 and 31 representing the day of the month. If you specify the dayValue parameter, you must also specify the monthValue.  


Description
If you do not specify the monthValue and dayValue parameters, the values returned from the getMonth and getDate methods are used.

If a parameter you specify is outside of the expected range, setFullYear attempts to update the other parameters and the date information in the Date object accordingly. For example, if you specify 15 for monthValue, the year is incremented by 1 (year + 1), and 3 is used for the month.


Examples
theBigDay = new Date();
theBigDay.setFullYear(1997);


See also
Date.getUTCFullYear ,Date.setUTCFullYear, Date.setYear


setHours

Sets the hours for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: Added minutesValue, secondsValue, and msValue parameters.  

ECMA version  

ECMA-262  


Syntax
setHours(hoursValue[, minutesValue, secondsValue, msValue])

Versions prior to JavaScript 1.3:

setHours(hoursValue)


Parameters



hoursValue

 

An integer between 0 and 23, representing the hour.  

minutesValue

 

An integer between 0 and 59, representing the minutes.  

secondsValue

 

An integer between 0 and 59, representing the seconds. If you specify the secondsValue parameter, you must also specify the minutesValue.  

msValue

 

A number between 0 and 999, representing the milliseconds. If you specify the msValue parameter, you must also specify the minutesValue and secondsValue.  


Description
If you do not specify the minutesValue, secondsValue, and msValue parameters, the values returned from the getUTCMinutes, getUTCSeconds, and getMilliseconds methods are used.

If a parameter you specify is outside of the expected range, setHours attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes will be incremented by 1 (min + 1), and 40 will be used for seconds.


Examples
theBigDay.setHours(7)


See also
Date.getHours, Date.setUTCHours


setMilliseconds

Sets the milliseconds for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setMilliseconds(millisecondsValue)


Parameters



millisecondsValue

 

A number between 0 and 999, representing the milliseconds.  


Description
If you specify a number outside the expected range, the date information in the Date object is updated accordingly. For example, if you specify 1005, the number of seconds is incremented by 1, and 5 is used for the milliseconds.


Examples
theBigDay = new Date();
theBigDay.setMilliseconds(100);


See also
Date.getMilliseconds , Date.setUTCMilliseconds


setMinutes

Sets the minutes for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: Added secondsValue and msValue parameters.  

ECMA version  

ECMA-262  


Syntax
setMinutes(minutesValue[, secondsValue, msValue])

Versions prior to JavaScript 1.3:

setMinutes(minutesValue)


Parameters



minutesValue

 

An integer between 0 and 59, representing the minutes.  

secondsValue

 

An integer between 0 and 59, representing the seconds. If you specify the secondsValue parameter, you must also specify the minutesValue.  

msValue

 

A number between 0 and 999, representing the milliseconds. If you specify the msValue parameter, you must also specify the minutesValue and secondsValue.  


Examples
theBigDay.setMinutes(45)


Description
If you do not specify the secondsValue and msValue parameters, the values returned from getSeconds and getMilliseconds methods are used.

If a parameter you specify is outside of the expected range, setMinutes attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes (minutesValue) will be incremented by 1 (minutesValue + 1), and 40 will be used for seconds.


See also
Date.getMinutes, Date.setUTCMilliseconds


setMonth

Sets the month for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: Added dayValue parameter.  

ECMA version  

ECMA-262  


Syntax
setMonth(monthValue[, dayValue])

Versions prior to JavaScript 1.3:

setMonth(monthValue)


Parameters



monthValue

 

An integer between 0 and 11 (representing the months January through December).  

dayValue

 

An integer from 1 to 31, representing the day of the month.  


Description
If you do not specify the dayValue parameter, the value returned from the getDate method is used.

If a parameter you specify is outside of the expected range, setMonth attempts to update the date information in the Date object accordingly. For example, if you use 15 for monthValue, the year will be incremented by 1 (year + 1), and 3 will be used for month.


Examples
theBigDay.setMonth(6)


See also
Date.getMonth, Date.setUTCMonth


setSeconds

Sets the seconds for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: Added msValue parameter.  

ECMA version  

ECMA-262  


Syntax
setSeconds(secondsValue[, msValue])

Versions prior to JavaScript 1.3:

setSeconds(secondsValue)


Parameters



secondsValue

 

An integer between 0 and 59.  

msValue

 

A number between 0 and 999, representing the milliseconds.  


Description
If you do not specify the msValue parameter, the value returned from the getMilliseconds methods is used.

If a parameter you specify is outside of the expected range, setSeconds attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes stored in the Date object will be incremented by 1, and 40 will be used for seconds.


Examples
theBigDay.setSeconds(30)


See also
Date.getSeconds, Date.setUTCSeconds


setTime

Sets the value of a Date object according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
setTime(timevalue)


Parameters



timevalue

 

An integer representing the number of milliseconds since 1 January 1970 00:00:00.  


Description
Use the setTime method to help assign a date and time to another Date object.


Examples
theBigDay = new Date("July 1, 1999")
sameAsBigDay = new Date()
sameAsBigDay.setTime(theBigDay.getTime())


See also
Date.getTime, Date.setUTCHours


setUTCDate

Sets the day of the month for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCDate(dayValue)


Parameters



dayValue

 

An integer from 1 to 31, representing the day of the month.  


Description
If a parameter you specify is outside of the expected range, setUTCDate attempts to update the date information in the Date object accordingly. For example, if you use 40 for dayValue, and the month stored in the Date object is June, the day will be changed to 10 and the month will be incremented to July.


Examples
theBigDay = new Date();
theBigDay.setUTCDate(20);


See also
Date.getUTCDate , Date.setDate


setUTCFullYear

Sets the full year for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCFullYear(yearValue[, monthValue, dayValue])


Parameters



yearValue

 

An integer specifying the numeric value of the year, for example, 1995.  

monthValue

 

An integer between 0 and 11 representing the months January through December.  

dayValue

 

An integer between 1 and 31 representing the day of the month. If you specify the dayValue parameter, you must also specify the monthValue.  


Description
If you do not specify the monthValue and dayValue parameters, the values returned from the getMonth and getDate methods are used.

If a parameter you specify is outside of the expected range, setUTCFullYear attempts to update the other parameters and the date information in the Date object accordingly. For example, if you specify 15 for monthValue, the year is incremented by 1 (year + 1), and 3 is used for the month.


Examples
theBigDay = new Date();
theBigDay.setUTCFullYear(1997);


See also
Date.getUTCFullYear , Date.setFullYear


setUTCHours

Sets the hour for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCHour(hoursValue[, minutesValue, secondsValue, msValue])


Parameters



hoursValue

 

An integer between 0 and 23, representing the hour.  

minutesValue

 

An integer between 0 and 59, representing the minutes.  

secondsValue

 

An integer between 0 and 59, representing the seconds. If you specify the secondsValue parameter, you must also specify the minutesValue.  

msValue

 

A number between 0 and 999, representing the milliseconds. If you specify the msValue parameter, you must also specify the minutesValue and secondsValue.  


Description
If you do not specify the minutesValue, secondsValue, and msValue parameters, the values returned from the getUTCMinutes, getUTCSeconds, and getUTCMilliseconds methods are used.

If a parameter you specify is outside of the expected range, setUTCHours attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes will be incremented by 1 (min + 1), and 40 will be used for seconds.


Examples
theBigDay = new Date();
theBigDay.setUTCHour(8);


See also
Date.getUTCHours , Date.setHours


setUTCMilliseconds

Sets the milliseconds for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCMilliseconds(millisecondsValue)


Parameters



millisecondsValue

 

A number between 0 and 999, representing the milliseconds.  


Description
If a parameter you specify is outside of the expected range, setUTCMilliseconds attempts to update the date information in the Date object accordingly. For example, if you use 1100 for millisecondsValue, the seconds stored in the Date object will be incremented by 1, and 100 will be used for milliseconds.


Examples
theBigDay = new Date();
theBigDay.setUTCMilliseconds(500);


See also
Date.getUTCMilliseconds , Date.setMilliseconds


setUTCMinutes

Sets the minutes for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCMinutes(minutesValue[, secondsValue, msValue])


Parameters



minutesValue

 

An integer between 0 and 59, representing the minutes.  

secondsValue

 

An integer between 0 and 59, representing the seconds. If you specify the secondsValue parameter, you must also specify the minutesValue.  

msValue

 

A number between 0 and 999, representing the milliseconds. If you specify the msValue parameter, you must also specify the minutesValue and secondsValue.  


Description
If you do not specify the secondsValue and msValue parameters, the values returned from getUTCSeconds and getUTCMilliseconds methods are used.

If a parameter you specify is outside of the expected range, setUTCMinutes attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes (minutesValue) will be incremented by 1 (minutesValue + 1), and 40 will be used for seconds.


Examples
theBigDay = new Date();
theBigDay.setUTCMinutes(43);


See also
Date.getUTCMinutes , Date.setMinutes


setUTCMonth

Sets the month for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCMonth(monthValue[, dayValue])


Parameters



monthValue

 

An integer between 0 and 11, representing the months January through December.  

dayValue

 

An integer from 1 to 31, representing the day of the month.  


Description
If you do not specify the dayValue parameter, the value returned from the getUTCDate method is used.

If a parameter you specify is outside of the expected range, setUTCMonth attempts to update the date information in the Date object accordingly. For example, if you use 15 for monthValue, the year will be incremented by 1 (year + 1), and 3 will be used for month.


Examples
theBigDay = new Date();
theBigDay.setUTCMonth(11);


See also
Date.getUTCMonth , Date.setMonth


setUTCSeconds

Sets the seconds for a specified date according to universal time.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
setUTCSeconds(secondsValue[, msValue])


Parameters



secondsValue

 

An integer between 0 and 59.  

msValue

 

A number between 0 and 999, representing the milliseconds.  


Description
If you do not specify the msValue parameter, the value returned from the getUTCMilliseconds methods is used.

If a parameter you specify is outside of the expected range, setUTCSeconds attempts to update the date information in the Date object accordingly. For example, if you use 100 for secondsValue, the minutes stored in the Date object will be incremented by 1, and 40 will be used for seconds.


Examples
theBigDay = new Date();
theBigDay.setUTCSeconds(20);


See also
Date.getUTCSeconds , Date.setSeconds


setYear

Sets the year for a specified date according to local time.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

Deprecated in JavaScript 1.3.  

ECMA version  

ECMA-262  


Syntax
setYear(yearValue)


Parameters



yearValue

 

An integer.  


Description
setYear is no longer used and has been replaced by the setFullYear method.

If yearValue is a number between 0 and 99 (inclusive), then the year for dateObjectName is set to 1900 + yearValue. Otherwise, the year for dateObjectName is set to yearValue.

To take into account years before and after 2000, you should use setFullYear instead of setYear so that the year is specified in full.


Examples
Note that there are two ways to set years in the 20th century.

Example 1. The year is set to 1996.

theBigDay.setYear(96)

Example 2. The year is set to 1996.

theBigDay.setYear(1996)

Example 3. The year is set to 2000.

theBigDay.setYear(2000)


See also
Date.getYear, Date.setFullYear, Date.setUTCFullYear


toGMTString

Converts a date to a string, using the Internet GMT conventions.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0

Deprecated in JavaScript 1.3.  

ECMA version  

ECMA-262  


Syntax
toGMTString()


Parameters
None


Description
toGMTString is no longer used and has been replaced by the toUTCString method.

The exact format of the value returned by toGMTString varies according to the platform.

You should use Date.toUTCString instead of toGMTSTring.


Examples
In the following example, today is a Date object:

today.toGMTString()

In this example, the toGMTString method converts the date to GMT (UTC) using the operating system's time-zone offset and returns a string value that is similar to the following form. The exact format depends on the platform.

Mon, 18 Dec 1995 17:28:35 GMT


See also
Date.toLocaleString, Date.toUTCString


toLocaleString

Converts a date to a string, using the current locale's conventions.



Method of  

Date  

Implemented in  

JavaScript 1.0, NES 2.0  

ECMA version  

ECMA-262  


Syntax
toLocaleString()


Parameters
None


Description
The toLocaleString method relies on the underlying operating system in formatting dates. It converts the date to a string using the formatting convention of the operating system where the script is running. For example, in the United States, the month appears before the date (04/15/98), whereas in Germany the date appears before the month (15.04.98). If the operating system is not year-2000 compliant and does not use the full year for years before 1900 or over 2000, toLocaleString returns a string that is not year-2000 compliant. toLocaleString behaves similarly to toString when converting a year that the operating system does not properly format.

Methods such as getHours, getMinutes, and getSeconds give more portable results than toLocaleString.


Examples
In the following example, today is a Date object:

today = new Date(95,11,18,17,28,35) //months are represented by 0 to 11
today.toLocaleString()

In this example, toLocaleString returns a string value that is similar to the following form. The exact format depends on the platform.

12/18/95 17:28:35


See also
Date.toGMTString, Date.toUTCString


toSource

Returns a string representing the source code of the object.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
toSource()


Parameters
None


Description
The toSource method returns the following values:

This method is usually called internally by JavaScript and not explicitly in code.


See also
Object.toSource


toString

Returns a string representing the specified Date object.



Method of  

Date  

Implemented in  

JavaScript 1.1, NES 2.0  

ECMA version  

ECMA-262  


Syntax
toString()


Parameters
None.


Description
The Date object overrides the toString method of the Object object; it does not inherit Object.toString. For Date objects, the toString method returns a string representation of the object.

JavaScript calls the toString method automatically when a date is to be represented as a text value or when a date is referred to in a string concatenation.


Examples
The following example assigns the toString value of a Date object to myVar:

x = new Date();
myVar=x.toString();   //assigns a value to myVar similar to:
     //Mon Sep 28 14:36:22 GMT-0700 (Pacific Daylight Time) 1998


See also
Object.toString


toUTCString

Converts a date to a string, using the universal time convention.



Method of  

Date  

Implemented in  

JavaScript 1.3  

ECMA version  

ECMA-262  


Syntax
toUTCString()


Parameters
None


Description
The value returned by toUTCString is a readable string formatted according to UTC convention. The format of the return value may vary according to the platform.


Examples
var UTCstring;
Today = new Date();
UTCstring = Today.toUTCString();


See also
Date.toLocaleString, Date.toUTCString


UTC

Returns the number of milliseconds in a Date object since January 1, 1970, 00:00:00, universal time.



Method of  

Date  

Static

Implemented in  

JavaScript 1.0, NES 2.0

JavaScript 1.3: added ms parameter.  

ECMA version  

ECMA-262  


Syntax
Date.UTC(year, month, day[, hrs, min, sec, ms])


Parameters



year

 

A year after 1900.  

month

 

An integer between 0 and 11 representing the month.  

date

 

An integer between 1 and 31 representing the day of the month.  

hrs

 

An integer between 0 and 23 representing the hours.  

min

 

An integer between 0 and 59 representing the minutes.  

sec

 

An integer between 0 and 59 representing the seconds.  

ms

 

An integer between 0 and 999 representing the milliseconds.  


Description
UTC takes comma-delimited date parameters and returns the number of milliseconds between January 1, 1970, 00:00:00, universal time and the time you specified.

You should specify a full year for the year; for example, 1998. If a year between 0 and 99 is specified, the method converts the year to a year in the 20th century (1900 + year); for example, if you specify 95, the year 1995 is used.

The UTC method differs from the Date constructor in two ways.

If a parameter you specify is outside of the expected range, the UTC method updates the other parameters to allow for your number. For example, if you use 15 for month, the year will be incremented by 1 (year + 1), and 3 will be used for the month.

Because UTC is a static method of Date, you always use it as Date.UTC(), rather than as a method of a Date object you created.


Examples
The following statement creates a Date object using GMT instead of local time:

gmtDate = new Date(Date.UTC(96, 11, 1, 0, 0, 0))


See also
Date.parse


valueOf

Returns the primitive value of a Date object.



Method of  

Date  

Implemented in  

JavaScript 1.1  

ECMA version  

ECMA-262  


Syntax
valueOf()


Parameters
None


Description
The valueOf method of Date returns the primitive value of a Date object as a number data type, the number of milliseconds since midnight 01 January, 1970 UTC.

This method is usually called internally by JavaScript and not explicitly in code.


Examples
x = new Date(56,6,17);
myVar=x.valueOf()      //assigns -424713600000 to myVar


See also
Object.valueOf


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Last Updated September 28, 2000