forked from lix-project/lix-website
39 lines
1.8 KiB
JavaScript
39 lines
1.8 KiB
JavaScript
'use strict';
|
||
|
||
var GetIntrinsic = require('get-intrinsic');
|
||
|
||
var $Date = GetIntrinsic('%Date%');
|
||
var $TypeError = require('es-errors/type');
|
||
|
||
var isNaN = require('../helpers/isNaN');
|
||
|
||
var callBound = require('call-bind/callBound');
|
||
|
||
var $indexOf = callBound('String.prototype.indexOf');
|
||
var $slice = callBound('String.prototype.slice');
|
||
var $toTimeString = callBound('Date.prototype.toTimeString');
|
||
|
||
// https://262.ecma-international.org/12.0/#sec-timezoneestring
|
||
|
||
module.exports = function TimeZoneString(tv) {
|
||
if (typeof tv !== 'number' || isNaN(tv)) {
|
||
throw new $TypeError('Assertion failed: `tv` must be a non-NaN Number'); // steps 1 - 2
|
||
}
|
||
|
||
// 3. Let offset be LocalTZA(tv, true).
|
||
// 4. If offset ≥ +0𝔽, then
|
||
// a. Let offsetSign be "+".
|
||
// b. Let absOffset be offset.
|
||
// 5. Else,
|
||
// a. Let offsetSign be "-".
|
||
// b. Let absOffset be -offset.
|
||
// 6. Let offsetMin be the String representation of MinFromTime(absOffset), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
|
||
// 7. Let offsetHour be the String representation of HourFromTime(absOffset), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
|
||
// 8. Let tzName be an implementation-defined string that is either the empty String or the string-concatenation of the code unit 0x0020 (SPACE), the code unit 0x0028 (LEFT PARENTHESIS), an implementation-defined timezone name, and the code unit 0x0029 (RIGHT PARENTHESIS).
|
||
// 9. Return the string-concatenation of offsetSign, offsetHour, offsetMin, and tzName.
|
||
|
||
// hack until LocalTZA, and "implementation-defined string" are available
|
||
var ts = $toTimeString(new $Date(tv));
|
||
return $slice(ts, $indexOf(ts, '(') + 1, $indexOf(ts, ')'));
|
||
};
|