@zenchef/date-fns-timezone
Version:
Parsing and formatting date strings using IANA time zones for date-fns.
145 lines (138 loc) • 6.88 kB
JavaScript
/** @module date-fns */
import parseDate from 'date-fns/parse'
import formatDate from 'date-fns/format'
import { findTimeZone, getUTCOffset } from '@zenchef/timezone-support'
/**
* @category Common Helpers
* @summary Format the date in the specified time zone.
*
* @description
* Returns the formatted date string in the given format, after converting it to the given time zone.
*
* The input date will be converted to the given time zone by default, using its UTC timestamp.
* If the local time in the input date is already in the given time zone, set `options.convertTimeZone`
* to `false`. Otherwise the date will be considered in local time and converted.
*
* The time zone has to be specified as a canonical name from the [IANA time zone list]{@link https://en.wikipedia.org/wiki/List_of_tz_database_time_zones}.
*
* The following tokens are recognized in the format string:
*
* | Unit | Token | Result examples |
* |-------------------------|-------|----------------------------------|
* | Month | M | 1, 2, ..., 12 |
* | | Mo | 1st, 2nd, ..., 12th |
* | | MM | 01, 02, ..., 12 |
* | | MMM | Jan, Feb, ..., Dec |
* | | MMMM | January, February, ..., December |
* | Quarter | Q | 1, 2, 3, 4 |
* | | Qo | 1st, 2nd, 3rd, 4th |
* | Day of month | D | 1, 2, ..., 31 |
* | | Do | 1st, 2nd, ..., 31st |
* | | DD | 01, 02, ..., 31 |
* | Day of year | DDD | 1, 2, ..., 366 |
* | | DDDo | 1st, 2nd, ..., 366th |
* | | DDDD | 001, 002, ..., 366 |
* | Day of week | d | 0, 1, ..., 6 |
* | | do | 0th, 1st, ..., 6th |
* | | dd | Su, Mo, ..., Sa |
* | | ddd | Sun, Mon, ..., Sat |
* | | dddd | Sunday, Monday, ..., Saturday |
* | Day of ISO week | E | 1, 2, ..., 7 |
* | ISO week | W | 1, 2, ..., 53 |
* | | Wo | 1st, 2nd, ..., 53rd |
* | | WW | 01, 02, ..., 53 |
* | Year | YY | 00, 01, ..., 99 |
* | | YYYY | 1900, 1901, ..., 2099 |
* | ISO week-numbering year | GG | 00, 01, ..., 99 |
* | | GGGG | 1900, 1901, ..., 2099 |
* | AM/PM | A | AM, PM |
* | | a | am, pm |
* | | aa | a.m., p.m. |
* | Hour | H | 0, 1, ... 23 |
* | | HH | 00, 01, ... 23 |
* | | h | 1, 2, ..., 12 |
* | | hh | 01, 02, ..., 12 |
* | Minute | m | 0, 1, ..., 59 |
* | | mm | 00, 01, ..., 59 |
* | Second | s | 0, 1, ..., 59 |
* | | ss | 00, 01, ..., 59 |
* | 1/10 of second | S | 0, 1, ..., 9 |
* | 1/100 of second | SS | 00, 01, ..., 99 |
* | Millisecond | SSS | 000, 001, ..., 999 |
* | Timezone abbreviation | z | CET, CEST, EST, EDT, ... |
* | Timezone offset to UTC | Z | -01:00, +00:00, ... +12:00 |
* | | ZZ | -0100, +0000, ..., +1200 |
* | Seconds timestamp | X | 512969520 |
* | Milliseconds timestamp | x | 512969520900 |
*
* The characters wrapped in square brackets are escaped.
*
* The result may vary by locale.
*
* @param {Date|String|Number} argument - the original date
* @param {String} formatString - the string of formatting tokens
* @param {Object} options - the object with options
* @param {Object} [options.locale=enLocale] - the locale object
* @param {String} options.timeZone - the canonical name of the target time zone
* @param {String} [options.convertTimeZone=true] - if the date should be converted to the given time zone before formatting
* @returns {String} the formatted date string
*
* @example
* // Represent midnight on 11 February 2014, UTC in middle-endian format, New York time:
* var result = formatToTimeZone(
* new Date(Date.UTC(2014, 1, 11)),
* 'MM/dd/yyyy h:mm A [GMT]Z (z)',
* { timeZone: 'America/New_York' }
* )
* // Returns '02/10/2014 7:00 PM GMT-0500 (EST)'
*
* @example
* // Represent noon on 2 July 2014 in Esperanto, Madrid time:
* var locale = require('date-fns/locale/eo')
* var result = formatToTimeZone(
* new Date(2014, 6, 2, 12),
* "HH:mm, do 'de' MMMM yyyy (Zz)",
* { locale, timeZone: 'Europe/Madrid', convertTimeZone: false }
* )
* // Returns '12:00, 2-a de julio 2014 (+02:00 CEST)'
*/
function formatToTimeZone (argument, formatString, options) {
let date = parseDate(argument)
let { timeZone, convertTimeZone } = options
timeZone = findTimeZone(timeZone)
timeZone = getUTCOffset(date, timeZone)
if (convertTimeZone !== false) {
const offset = timeZone.offset - date.getTimezoneOffset()
date = new Date(date.getTime() - offset * 60 * 1000)
}
formatString = formatTimeZoneTokens(formatString, timeZone)
return formatDate(date, formatString, options)
}
function padToTwoDigits (number) {
return number > 9 ? number : `0${number}`
}
function formatTimeZoneOffset (offset, separator) {
let sign
if (offset <= 0) {
offset = -offset
sign = '+'
} else {
sign = '-'
}
const hours = padToTwoDigits(Math.floor(offset / 60))
const minutes = padToTwoDigits(offset % 60)
return sign + hours + separator + minutes
}
function formatTimeZoneTokens (format, timeZone) {
return format.replace(/z|ZZ?/g, match => {
switch (match) {
case 'z':
return `[${timeZone.abbreviation}]`
case 'Z':
return formatTimeZoneOffset(timeZone.offset, ':')
default: // 'ZZ'
return formatTimeZoneOffset(timeZone.offset, '')
}
})
}
export { formatToTimeZone }