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Створює екземляр об'єкту JavaScript Date, який вказує на певний момент часу.

Об'єкти Date рахують час у мілісекундах. Точкою відліку є 1 січня 1970 р по UTC.    

Синтаксис

new Date();
new Date(value);
new Date(dateString);
new Date(year, month[, date[, hours[, minutes[, seconds[, milliseconds]]]]]);

Примітка: Об'єкти JavaScript Date можуть бути створені лише викликом JavaScript Date як конструктора: виклик Date як звичайної функції (тобто, без оператора new) поверне строку, а не об'єкт Date; на відміну від інших типів об'єктів JavaScript, об'єкти Date не мають літерального синтаксису.

Параметри

Note: Where Date is called as a constructor with more than one argument, if values are greater than their logical range (e.g. 13 is provided as the month value or 70 for the minute value), the adjacent value will be adjusted. E.g. new Date(2013, 13, 1) is equivalent to new Date(2014, 1, 1), both create a date for 2014-02-01 (note that the month is 0-based). Similarly for other values: new Date(2013, 2, 1, 0, 70) is equivalent to new Date(2013, 2, 1, 1, 10) which both create a date for 2013-03-01T01:10:00.

Note: Where Date is called as a constructor with more than one argument, the specifed arguments represent local time. If UTC is desired, use new Date(Date.UTC(...)) with the same arguments.

value
Ціле значення, яке вказує кількість мілісекунд з 1 січня 1970 року 00:00:00 UTC, без високосних секунд (Unix Epoch; але майте на увазі, що більшість функцій часу та дати Unix рахують у секундах).
dateString
Строкове значення, яке вказує дату. Строка має бути у форматі, який розпізнається методом Date.parse() (IETF-compliant RFC 2822 timestamps, і також version of ISO8601).

Note: parsing of date strings with the Date constructor (and Date.parse, they are equivalent) is strongly discouraged due to browser differences and inconsistencies. Support for RFC 2822 format strings is by convention only. Support for ISO 8601 formats differs in that date-only strings (e.g. "1970-01-01") are treated as UTC, not local.

year
Ціле значення, яке вказує на рік. Значення від 0 до 99 вказують на роки з 1900 до 1999.  Дивіться example below.
month
Ціле значення, яке вказує на місяць. 0 вказує на січень. 11 вказує на грудень.
date
Не обов'язкове. Ціле значення, яке вказує день місяця.
hours
Не обов'язкове. Ціле значення, яке вказує годину доби.
minutes
Не обов'язкове. Ціле значення, яке вказує хвилину.
seconds
Не обов'язкове. Ціле значення, яке вказує секунду.
milliseconds
Не обов'язкове. Ціле значення, яке вказує мілісекунду.

Description

  • If no arguments are provided, the constructor creates a JavaScript Date object for the current date and time according to system settings.
  • If at least two arguments are supplied, missing arguments are either set to 1 (if day is missing) or 0 for all others.
  • The JavaScript date is based on a time value that is milliseconds since midnight 01 January, 1970 UTC. A day holds 86,400,000 milliseconds. The JavaScript Date object range is -100,000,000 days to 100,000,000 days relative to 01 January, 1970 UTC.
  • The JavaScript Date object provides uniform behavior across platforms. The time value can be passed between systems to create a date that represents the same moment in time.
  • The JavaScript 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.
  • Invoking JavaScript Date as a function (i.e., without the new operator) will return a string representing the current date and time.

Властивості

Date.prototype
Дозволяє додавання властивостей до об'єкта JavaScript Date.
Date.length
Значення Date.length дорівнює 7. Це кількість аргументів у конструкторі.

Методи

Date.now()
Повертає кількість мілісекунд між поточним часом та 1 січнем1970 00:00:00. Секунди не враховуються.
Date.parse()
Парсить (Parses) текстову змінну з датою і повертає кількість мілісекунд від 1 січня 1970 00:00:00 по UTC. Секунди не враховуються.

Note: Parsing of strings with Date.parse is strongly discouraged due to browser differences and inconsistencies.

Date.UTC()
Accepts the same parameters as the longest form of the constructor (i.e. 2 to 7) and returns the number of milliseconds since 1 January, 1970, 00:00:00 UTC, with leap seconds ignored.

JavaScript Date instances

All Date instances inherit from Date.prototype. The prototype object of the Date constructor can be modified to affect all Date instances.

Date.prototype Methods

Getter

Date.prototype.getDate()
Returns the day of the month (1-31) for the specified date according to local time.
Date.prototype.getDay()
Returns the day of the week (0-6) for the specified date according to local time.
Date.prototype.getFullYear()
Returns the year (4 digits for 4-digit years) of the specified date according to local time.
Date.prototype.getHours()
Returns the hour (0-23) in the specified date according to local time.
Date.prototype.getMilliseconds()
Returns the milliseconds (0-999) in the specified date according to local time.
Date.prototype.getMinutes()
Returns the minutes (0-59) in the specified date according to local time.
Date.prototype.getMonth()
Returns the month (0-11) in the specified date according to local time.
Date.prototype.getSeconds()
Returns the seconds (0-59) in the specified date according to local time.
Date.prototype.getTime()
Returns the numeric value of the specified date as the number of milliseconds since January 1, 1970, 00:00:00 UTC (negative for prior times).
Date.prototype.getTimezoneOffset()
Returns the time-zone offset in minutes for the current locale.
Date.prototype.getUTCDate()
Returns the day (date) of the month (1-31) in the specified date according to universal time.
Date.prototype.getUTCDay()
Returns the day of the week (0-6) in the specified date according to universal time.
Date.prototype.getUTCFullYear()
Returns the year (4 digits for 4-digit years) in the specified date according to universal time.
Date.prototype.getUTCHours()
Returns the hours (0-23) in the specified date according to universal time.
Date.prototype.getUTCMilliseconds()
Returns the milliseconds (0-999) in the specified date according to universal time.
Date.prototype.getUTCMinutes()
Returns the minutes (0-59) in the specified date according to universal time.
Date.prototype.getUTCMonth()
Returns the month (0-11) in the specified date according to universal time.
Date.prototype.getUTCSeconds()
Returns the seconds (0-59) in the specified date according to universal time.
Date.prototype.getYear()
Returns the year (usually 2-3 digits) in the specified date according to local time. Use getFullYear() instead.

Setter

Date.prototype.setDate()
Sets the day of the month for a specified date according to local time.
Date.prototype.setFullYear()
Sets the full year (e.g. 4 digits for 4-digit years) for a specified date according to local time.
Date.prototype.setHours()
Sets the hours for a specified date according to local time.
Date.prototype.setMilliseconds()
Sets the milliseconds for a specified date according to local time.
Date.prototype.setMinutes()
Sets the minutes for a specified date according to local time.
Date.prototype.setMonth()
Sets the month for a specified date according to local time.
Date.prototype.setSeconds()
Sets the seconds for a specified date according to local time.
Date.prototype.setTime()
Sets the Date object to the time represented by a number of milliseconds since January 1, 1970, 00:00:00 UTC, allowing for negative numbers for times prior.
Date.prototype.setUTCDate()
Sets the day of the month for a specified date according to universal time.
Date.prototype.setUTCFullYear()
Sets the full year (e.g. 4 digits for 4-digit years) for a specified date according to universal time.
Date.prototype.setUTCHours()
Sets the hour for a specified date according to universal time.
Date.prototype.setUTCMilliseconds()
Sets the milliseconds for a specified date according to universal time.
Date.prototype.setUTCMinutes()
Sets the minutes for a specified date according to universal time.
Date.prototype.setUTCMonth()
Sets the month for a specified date according to universal time.
Date.prototype.setUTCSeconds()
Sets the seconds for a specified date according to universal time.
Date.prototype.setYear()
Sets the year (usually 2-3 digits) for a specified date according to local time. Use setFullYear() instead.

Conversion getter

Date.prototype.toDateString()
Returns the "date" portion of the Date as a human-readable string.
Date.prototype.toISOString()
Converts a date to a string following the ISO 8601 Extended Format.
Date.prototype.toJSON()
Returns a string representing the Date using toISOString(). Intended for use by JSON.stringify().
Date.prototype.toGMTString()
Returns a string representing the Date based on the GMT (UT) time zone. Use toUTCString() instead.
Date.prototype.toLocaleDateString()
Returns a string with a locality sensitive representation of the date portion of this date based on system settings.
Date.prototype.toLocaleFormat()
Converts a date to a string, using a format string.
Date.prototype.toLocaleString()
Returns a string with a locality sensitive representation of this date. Overrides the Object.prototype.toLocaleString() method.
Date.prototype.toLocaleTimeString()
Returns a string with a locality sensitive representation of the time portion of this date based on system settings.
Date.prototype.toSource()
Returns a string representing the source for an equivalent Date object; you can use this value to create a new object. Overrides the Object.prototype.toSource() method.
Date.prototype.toString()
Returns a string representing the specified Date object. Overrides the Object.prototype.toString() method.
Date.prototype.toTimeString()
Returns the "time" portion of the Date as a human-readable string.
Date.prototype.toUTCString()
Converts a date to a string using the UTC timezone.
Date.prototype.valueOf()
Returns the primitive value of a Date object. Overrides the Object.prototype.valueOf() method.

Examples

Several ways to create a Date object

The following examples show several ways to create JavaScript dates:

Note: parsing of date strings with the Date constructor (and Date.parse, they are equivalent) is strongly discouraged due to browser differences and inconsistencies.

var today = new Date();
var birthday = new Date('December 17, 1995 03:24:00');
var birthday = new Date('1995-12-17T03:24:00');
var birthday = new Date(1995, 11, 17);
var birthday = new Date(1995, 11, 17, 3, 24, 0);

Two digit years map to 1900 - 1999

In order to create and get dates between the years 0 and 99 the Date.prototype.setFullYear() and Date.prototype.getFullYear() methods should be used.

var date = new Date(98, 1); // Sun Feb 01 1998 00:00:00 GMT+0000 (GMT)

// Deprecated method, 98 maps to 1998 here as well
date.setYear(98);           // Sun Feb 01 1998 00:00:00 GMT+0000 (GMT)

date.setFullYear(98);       // Sat Feb 01 0098 00:00:00 GMT+0000 (BST)

Calculating elapsed time

The following examples show how to determine the elapsed time between two JavaScript dates in millisconds.

Due to the differing lengths of days (due to daylight saving changeover), months and years, expressing elapsed time in units greater than hours, minutes and seconds requires addressing a number of issues and should be thoroughly researched before being attempted.

// using Date objects
var start = Date.now();

// the event to time goes here:
doSomethingForALongTime();
var end = Date.now();
var elapsed = end - start; // elapsed time in milliseconds
// using built-in methods
var start = new Date();

// the event to time goes here:
doSomethingForALongTime();
var end = new Date();
var elapsed = end.getTime() - start.getTime(); // elapsed time in milliseconds
// to test a function and get back its return
function printElapsedTime(fTest) {
  var nStartTime = Date.now(),
      vReturn = fTest(),
      nEndTime = Date.now();

  console.log('Elapsed time: ' + String(nEndTime - nStartTime) + ' milliseconds');
  return vReturn;
}

yourFunctionReturn = printElapsedTime(yourFunction);

Note: In browsers that support the Web Performance API's high-resolution time feature, Performance.now() can provide more reliable and precise measurements of elapsed time than Date.now().

Specifications

Specification Status Comment
ECMAScript Latest Draft (ECMA-262)
The definition of 'Date' in that specification.
Living Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Date' in that specification.
Standard  
ECMAScript 5.1 (ECMA-262)
The definition of 'Date' in that specification.
Standard  
ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.1.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) [1] (Yes) (Yes) [1] (Yes) [2] (Yes) [1] (Yes) [1]
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

[1] Some browsers can have issues when parsing dates: 3/14/2012 blog from danvk Comparing FF/IE/Chrome on Parsing Date Strings

[2] ISO8601 Date Format is not supported in Internet Explorer 8, and other version can have issues when parsing dates

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 Зробили внесок у цю сторінку: DariaManko, bsurai
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