Related
Goal: Find the local time and UTC time offset then construct the URL in following format.
Example URL: /Actions/Sleep?duration=2002-10-10T12:00:00−05:00
The format is based on the W3C recommendation. The documentation says:
For example, 2002-10-10T12:00:00−05:00 (noon on 10 October 2002,
Central Daylight Savings Time as well as Eastern Standard Time in the U.S.)
is equal to 2002-10-10T17:00:00Z, five hours later than 2002-10-10T12:00:00Z.
So based on my understanding, I need to find my local time by new Date() then use getTimezoneOffset() function to compute the difference then attach it to the end of string.
Get local time with format
var local = new Date().format("yyyy-MM-ddThh:mm:ss"); // 2013-07-02T09:00:00
Get UTC time offset by hour
var offset = local.getTimezoneOffset() / 60; // 7
Construct URL (time part only)
var duration = local + "-" + offset + ":00"; // 2013-07-02T09:00:00-7:00
The above output means my local time is 2013/07/02 9am and difference from UTC is 7 hours (UTC is 7 hours ahead of local time)
So far it seems to work but what if getTimezoneOffset() returns negative value like -120?
I'm wondering how the format should look like in such case because I cannot figure out from W3C documentation.
Here's a simple helper function that will format JS dates for you.
function toIsoString(date) {
var tzo = -date.getTimezoneOffset(),
dif = tzo >= 0 ? '+' : '-',
pad = function(num) {
return (num < 10 ? '0' : '') + num;
};
return date.getFullYear() +
'-' + pad(date.getMonth() + 1) +
'-' + pad(date.getDate()) +
'T' + pad(date.getHours()) +
':' + pad(date.getMinutes()) +
':' + pad(date.getSeconds()) +
dif + pad(Math.floor(Math.abs(tzo) / 60)) +
':' + pad(Math.abs(tzo) % 60);
}
var dt = new Date();
console.log(toIsoString(dt));
getTimezoneOffset() returns the opposite sign of the format required by the spec that you referenced.
This format is also known as ISO8601, or more precisely as RFC3339.
In this format, UTC is represented with a Z while all other formats are represented by an offset from UTC. The meaning is the same as JavaScript's, but the order of subtraction is inverted, so the result carries the opposite sign.
Also, there is no method on the native Date object called format, so your function in #1 will fail unless you are using a library to achieve this. Refer to this documentation.
If you are seeking a library that can work with this format directly, I recommend trying moment.js. In fact, this is the default format, so you can simply do this:
var m = moment(); // get "now" as a moment
var s = m.format(); // the ISO format is the default so no parameters are needed
// sample output: 2013-07-01T17:55:13-07:00
This is a well-tested, cross-browser solution, and has many other useful features.
I think it is worth considering that you can get the requested info with just a single API call to the standard library...
new Date().toLocaleString( 'sv', { timeZoneName: 'short' } );
// produces "2019-10-30 15:33:47 GMT−4"
You would have to do text swapping if you want to add the 'T' delimiter, remove the 'GMT-', or append the ':00' to the end.
But then you can easily play with the other options if you want to eg. use 12h time or omit the seconds etc.
Note that I'm using Sweden as locale because it is one of the countries that uses ISO 8601 format. I think most of the ISO countries use this 'GMT-4' format for the timezone offset other then Canada which uses the time zone abbreviation eg. "EDT" for eastern-daylight-time.
You can get the same thing from the newer standard i18n function "Intl.DateTimeFormat()"
but you have to tell it to include the time via the options or it will just give date.
My answer is a slight variation for those who just want today's date in the local timezone in the YYYY-MM-DD format.
Let me be clear:
My Goal: get today's date in the user's timezone but formatted as ISO8601 (YYYY-MM-DD)
Here is the code:
new Date().toLocaleDateString("sv") // "2020-02-23" //
This works because the Sweden locale uses the ISO 8601 format.
This is my function for the clients timezone, it's lite weight and simple
function getCurrentDateTimeMySql() {
var tzoffset = (new Date()).getTimezoneOffset() * 60000; //offset in milliseconds
var localISOTime = (new Date(Date.now() - tzoffset)).toISOString().slice(0, 19).replace('T', ' ');
var mySqlDT = localISOTime;
return mySqlDT;
}
Check this:
function dateToLocalISO(date) {
const off = date.getTimezoneOffset()
const absoff = Math.abs(off)
return (new Date(date.getTime() - off*60*1000).toISOString().substr(0,23) +
(off > 0 ? '-' : '+') +
Math.floor(absoff / 60).toFixed(0).padStart(2,'0') + ':' +
(absoff % 60).toString().padStart(2,'0'))
}
// Test it:
d = new Date()
dateToLocalISO(d)
// ==> '2019-06-21T16:07:22.181-03:00'
// Is similar to:
moment = require('moment')
moment(d).format('YYYY-MM-DDTHH:mm:ss.SSSZ')
// ==> '2019-06-21T16:07:22.181-03:00'
You can achieve this with a few simple extension methods. The following Date extension method returns just the timezone component in ISO format, then you can define another for the date/time part and combine them for a complete date-time-offset string.
Date.prototype.getISOTimezoneOffset = function () {
const offset = this.getTimezoneOffset();
return (offset < 0 ? "+" : "-") + Math.floor(Math.abs(offset / 60)).leftPad(2) + ":" + (Math.abs(offset % 60)).leftPad(2);
}
Date.prototype.toISOLocaleString = function () {
return this.getFullYear() + "-" + (this.getMonth() + 1).leftPad(2) + "-" +
this.getDate().leftPad(2) + "T" + this.getHours().leftPad(2) + ":" +
this.getMinutes().leftPad(2) + ":" + this.getSeconds().leftPad(2) + "." +
this.getMilliseconds().leftPad(3);
}
Number.prototype.leftPad = function (size) {
var s = String(this);
while (s.length < (size || 2)) {
s = "0" + s;
}
return s;
}
Example usage:
var date = new Date();
console.log(date.toISOLocaleString() + date.getISOTimezoneOffset());
// Prints "2020-08-05T16:15:46.525+10:00"
I know it's 2020 and most people are probably using Moment.js by now, but a simple copy & pastable solution is still sometimes handy to have.
(The reason I split the date/time and offset methods is because I'm using an old Datejs library which already provides a flexible toString method with custom format specifiers, but just doesn't include the timezone offset. Hence, I added toISOLocaleString for anyone without said library.)
Just my two cents here
I was facing this issue with datetimes so what I did is this:
const moment = require('moment-timezone')
const date = moment.tz('America/Bogota').format()
Then save date to db to be able to compare it from some query.
To install moment-timezone
npm i moment-timezone
No moment.js needed: Here's a full round trip answer, from an input type of "datetime-local" which outputs an ISOLocal string to UTCseconds at GMT and back:
<input type="datetime-local" value="2020-02-16T19:30">
isoLocal="2020-02-16T19:30"
utcSeconds=new Date(isoLocal).getTime()/1000
//here you have 1581899400 for utcSeconds
let isoLocal=new Date(utcSeconds*1000-new Date().getTimezoneOffset()*60000).toISOString().substring(0,16)
2020-02-16T19:30
date to ISO string,
with local(computer) time zone,
with or without milliseconds
ISO ref: https://en.wikipedia.org/wiki/ISO_8601
how to use: toIsoLocalTime(new Date())
function toIsoLocalTime(value) {
if (value instanceof Date === false)
value = new Date();
const off = value.getTimezoneOffset() * -1;
const del = value.getMilliseconds() ? 'Z' : '.'; // have milliseconds ?
value = new Date(value.getTime() + off * 60000); // add or subtract time zone
return value
.toISOString()
.split(del)[0]
+ (off < 0 ? '-' : '+')
+ ('0' + Math.abs(Math.floor(off / 60))).substr(-2)
+ ':'
+ ('0' + Math.abs(off % 60)).substr(-2);
}
function test(value) {
const event = new Date(value);
console.info(value + ' -> ' + toIsoLocalTime(event) + ', test = ' + (event.getTime() === (new Date(toIsoLocalTime(event))).getTime() ));
}
test('2017-06-14T10:00:00+03:00'); // test with timezone
test('2017-06-14T10:00:00'); // test with local timezone
test('2017-06-14T10:00:00Z'); // test with UTC format
test('2099-12-31T23:59:59.999Z'); // date with milliseconds
test((new Date()).toString()); // now
consider using moment (like Matt's answer).
From version 2.20.0, you may call .toISOString(true) to prevent UTC conversion:
console.log(moment().toISOString(true));
// sample output: 2022-04-06T16:26:36.758+03:00
Use Temporal.
Temporal.Now.zonedDateTimeISO().toString()
// '2022-08-09T14:16:47.762797591-07:00[America/Los_Angeles]'
To omit the fractional seconds and IANA time zone:
Temporal.Now.zonedDateTimeISO().toString({
timeZoneName: "never",
fractionalSecondDigits: 0
})
// '2022-08-09T14:18:34-07:00'
Note: Temporal is currently (2022) available as a polyfill, but will soon be available in major browsers.
With luxon:
DateTime.now().toISODate() // 2022-05-23
Here are the functions I used for this end:
function localToGMTStingTime(localTime = null) {
var date = localTime ? new Date(localTime) : new Date();
return new Date(date.getTime() + (date.getTimezoneOffset() * 60000)).toISOString();
};
function GMTToLocalStingTime(GMTTime = null) {
var date = GMTTime ? new Date(GMTTime) : new Date();;
return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString();
};
let myDate = new Date(dateToBeFormatted * 1000); // depends if you have milliseconds, or seconds, then the * 1000 might be not, or required.
timeOffset = myDate.getTimezoneOffset();
myDate = new Date(myDate.getTime() - (timeOffset * 60 * 1000));
console.log(myDate.toISOString().split('T')[0]);
Inspired by https://stackoverflow.com/a/29774197/11127383, including timezone offset comment.
a simple way to get:
//using a sample date
let iso_str = '2022-06-11T01:51:59.618Z';
let d = new Date(iso_str);
let tz = 'America/Santiago'
let options = {
timeZone:tz ,
timeZoneName:'longOffset',
year: 'numeric',
month: 'numeric',
day: 'numeric',
hour: 'numeric',
minute: 'numeric',
second: 'numeric',
fractionalSecondDigits: 3
}
str_locale = d.toLocaleString("sv-SE",options);
iso_str_tz = str_locale.replace(/(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2}),(\d+)\s+/,'$1-$2-$3T$4:$5:$6.$7').replace('GMT−', '-' ).replace('GMT+','+')
console.log('iso_str : ',iso_str);
console.log('str_locale : ',str_locale);
console.log('iso_str_tz : ',iso_str_tz);
console.log('iso_str_tz --> date : ',new Date(iso_str_tz));
console.log('iso_str_tz --> iso_str: ',new Date(iso_str_tz).toISOString());
Using moment.js, you can use keepOffset parameter of toISOString:
toISOString(keepOffset?: boolean): string;
moment().toISOString(true)
Alternative approach with dayjs
import dayjs from "dayjs"
const formattedDateTime = dayjs(new Date()).format()
console.log(formattedDateTime) // Prints 2022-11-09T07:49:29+03:00
Here's another way a convert your date with an offset.
function toCustomDateString(date, offset) {
function pad(number) {
if (number < 10) {
return "0" + number;
}
return number;
}
var offsetHours = offset / 60;
var offsetMinutes = offset % 60;
var sign = (offset > 0) ? "+" : "-";
offsetHours = pad(Math.floor(Math.abs(offsetHours)));
offsetMinutes = pad(Math.abs(offsetMinutes));
return date.getFullYear() +
"-" + pad(date.getMonth() + 1) +
"-" + pad(date.getDate()) +
"T" + pad(date.getHours()) +
":" + pad(date.getMinutes()) +
":" + pad(date.getSeconds()) +
sign + offsetHours +
":" + offsetMinutes;
}
Then you can use it like this:
var date = new Date();
var offset = 330; // offset in minutes from UTC, for India it is 330 minutes ahead of UTC
var customDateString = toCustomDateString(date, offset);
console.log(customDateString);
// Output: "2023-02-09T10:29:31+05:30"
function setDate(){
var now = new Date();
now.setMinutes(now.getMinutes() - now.getTimezoneOffset());
var timeToSet = now.toISOString().slice(0,16);
/*
If you have an element called "eventDate" like the following:
<input type="datetime-local" name="eventdate" id="eventdate" />
and you would like to set the current and minimum time then use the following:
*/
var elem = document.getElementById("eventDate");
elem.value = timeToSet;
elem.min = timeToSet;
}
I found another more easy solution:
let now = new Date();
// correct time zone offset for generating iso string
now.setMinutes(now.getMinutes() - now.getTimezoneOffset())
now = now.toISOString();
I undo the timezone offset by substracting it from the current date object.
The UTC time from the date object is now pointing to the local time.
That gives you the possibility to get the iso date for the local time.
Goal: Find the local time and UTC time offset then construct the URL in following format.
Example URL: /Actions/Sleep?duration=2002-10-10T12:00:00−05:00
The format is based on the W3C recommendation. The documentation says:
For example, 2002-10-10T12:00:00−05:00 (noon on 10 October 2002,
Central Daylight Savings Time as well as Eastern Standard Time in the U.S.)
is equal to 2002-10-10T17:00:00Z, five hours later than 2002-10-10T12:00:00Z.
So based on my understanding, I need to find my local time by new Date() then use getTimezoneOffset() function to compute the difference then attach it to the end of string.
Get local time with format
var local = new Date().format("yyyy-MM-ddThh:mm:ss"); // 2013-07-02T09:00:00
Get UTC time offset by hour
var offset = local.getTimezoneOffset() / 60; // 7
Construct URL (time part only)
var duration = local + "-" + offset + ":00"; // 2013-07-02T09:00:00-7:00
The above output means my local time is 2013/07/02 9am and difference from UTC is 7 hours (UTC is 7 hours ahead of local time)
So far it seems to work but what if getTimezoneOffset() returns negative value like -120?
I'm wondering how the format should look like in such case because I cannot figure out from W3C documentation.
Here's a simple helper function that will format JS dates for you.
function toIsoString(date) {
var tzo = -date.getTimezoneOffset(),
dif = tzo >= 0 ? '+' : '-',
pad = function(num) {
return (num < 10 ? '0' : '') + num;
};
return date.getFullYear() +
'-' + pad(date.getMonth() + 1) +
'-' + pad(date.getDate()) +
'T' + pad(date.getHours()) +
':' + pad(date.getMinutes()) +
':' + pad(date.getSeconds()) +
dif + pad(Math.floor(Math.abs(tzo) / 60)) +
':' + pad(Math.abs(tzo) % 60);
}
var dt = new Date();
console.log(toIsoString(dt));
getTimezoneOffset() returns the opposite sign of the format required by the spec that you referenced.
This format is also known as ISO8601, or more precisely as RFC3339.
In this format, UTC is represented with a Z while all other formats are represented by an offset from UTC. The meaning is the same as JavaScript's, but the order of subtraction is inverted, so the result carries the opposite sign.
Also, there is no method on the native Date object called format, so your function in #1 will fail unless you are using a library to achieve this. Refer to this documentation.
If you are seeking a library that can work with this format directly, I recommend trying moment.js. In fact, this is the default format, so you can simply do this:
var m = moment(); // get "now" as a moment
var s = m.format(); // the ISO format is the default so no parameters are needed
// sample output: 2013-07-01T17:55:13-07:00
This is a well-tested, cross-browser solution, and has many other useful features.
I think it is worth considering that you can get the requested info with just a single API call to the standard library...
new Date().toLocaleString( 'sv', { timeZoneName: 'short' } );
// produces "2019-10-30 15:33:47 GMT−4"
You would have to do text swapping if you want to add the 'T' delimiter, remove the 'GMT-', or append the ':00' to the end.
But then you can easily play with the other options if you want to eg. use 12h time or omit the seconds etc.
Note that I'm using Sweden as locale because it is one of the countries that uses ISO 8601 format. I think most of the ISO countries use this 'GMT-4' format for the timezone offset other then Canada which uses the time zone abbreviation eg. "EDT" for eastern-daylight-time.
You can get the same thing from the newer standard i18n function "Intl.DateTimeFormat()"
but you have to tell it to include the time via the options or it will just give date.
My answer is a slight variation for those who just want today's date in the local timezone in the YYYY-MM-DD format.
Let me be clear:
My Goal: get today's date in the user's timezone but formatted as ISO8601 (YYYY-MM-DD)
Here is the code:
new Date().toLocaleDateString("sv") // "2020-02-23" //
This works because the Sweden locale uses the ISO 8601 format.
This is my function for the clients timezone, it's lite weight and simple
function getCurrentDateTimeMySql() {
var tzoffset = (new Date()).getTimezoneOffset() * 60000; //offset in milliseconds
var localISOTime = (new Date(Date.now() - tzoffset)).toISOString().slice(0, 19).replace('T', ' ');
var mySqlDT = localISOTime;
return mySqlDT;
}
Check this:
function dateToLocalISO(date) {
const off = date.getTimezoneOffset()
const absoff = Math.abs(off)
return (new Date(date.getTime() - off*60*1000).toISOString().substr(0,23) +
(off > 0 ? '-' : '+') +
Math.floor(absoff / 60).toFixed(0).padStart(2,'0') + ':' +
(absoff % 60).toString().padStart(2,'0'))
}
// Test it:
d = new Date()
dateToLocalISO(d)
// ==> '2019-06-21T16:07:22.181-03:00'
// Is similar to:
moment = require('moment')
moment(d).format('YYYY-MM-DDTHH:mm:ss.SSSZ')
// ==> '2019-06-21T16:07:22.181-03:00'
You can achieve this with a few simple extension methods. The following Date extension method returns just the timezone component in ISO format, then you can define another for the date/time part and combine them for a complete date-time-offset string.
Date.prototype.getISOTimezoneOffset = function () {
const offset = this.getTimezoneOffset();
return (offset < 0 ? "+" : "-") + Math.floor(Math.abs(offset / 60)).leftPad(2) + ":" + (Math.abs(offset % 60)).leftPad(2);
}
Date.prototype.toISOLocaleString = function () {
return this.getFullYear() + "-" + (this.getMonth() + 1).leftPad(2) + "-" +
this.getDate().leftPad(2) + "T" + this.getHours().leftPad(2) + ":" +
this.getMinutes().leftPad(2) + ":" + this.getSeconds().leftPad(2) + "." +
this.getMilliseconds().leftPad(3);
}
Number.prototype.leftPad = function (size) {
var s = String(this);
while (s.length < (size || 2)) {
s = "0" + s;
}
return s;
}
Example usage:
var date = new Date();
console.log(date.toISOLocaleString() + date.getISOTimezoneOffset());
// Prints "2020-08-05T16:15:46.525+10:00"
I know it's 2020 and most people are probably using Moment.js by now, but a simple copy & pastable solution is still sometimes handy to have.
(The reason I split the date/time and offset methods is because I'm using an old Datejs library which already provides a flexible toString method with custom format specifiers, but just doesn't include the timezone offset. Hence, I added toISOLocaleString for anyone without said library.)
Just my two cents here
I was facing this issue with datetimes so what I did is this:
const moment = require('moment-timezone')
const date = moment.tz('America/Bogota').format()
Then save date to db to be able to compare it from some query.
To install moment-timezone
npm i moment-timezone
No moment.js needed: Here's a full round trip answer, from an input type of "datetime-local" which outputs an ISOLocal string to UTCseconds at GMT and back:
<input type="datetime-local" value="2020-02-16T19:30">
isoLocal="2020-02-16T19:30"
utcSeconds=new Date(isoLocal).getTime()/1000
//here you have 1581899400 for utcSeconds
let isoLocal=new Date(utcSeconds*1000-new Date().getTimezoneOffset()*60000).toISOString().substring(0,16)
2020-02-16T19:30
date to ISO string,
with local(computer) time zone,
with or without milliseconds
ISO ref: https://en.wikipedia.org/wiki/ISO_8601
how to use: toIsoLocalTime(new Date())
function toIsoLocalTime(value) {
if (value instanceof Date === false)
value = new Date();
const off = value.getTimezoneOffset() * -1;
const del = value.getMilliseconds() ? 'Z' : '.'; // have milliseconds ?
value = new Date(value.getTime() + off * 60000); // add or subtract time zone
return value
.toISOString()
.split(del)[0]
+ (off < 0 ? '-' : '+')
+ ('0' + Math.abs(Math.floor(off / 60))).substr(-2)
+ ':'
+ ('0' + Math.abs(off % 60)).substr(-2);
}
function test(value) {
const event = new Date(value);
console.info(value + ' -> ' + toIsoLocalTime(event) + ', test = ' + (event.getTime() === (new Date(toIsoLocalTime(event))).getTime() ));
}
test('2017-06-14T10:00:00+03:00'); // test with timezone
test('2017-06-14T10:00:00'); // test with local timezone
test('2017-06-14T10:00:00Z'); // test with UTC format
test('2099-12-31T23:59:59.999Z'); // date with milliseconds
test((new Date()).toString()); // now
consider using moment (like Matt's answer).
From version 2.20.0, you may call .toISOString(true) to prevent UTC conversion:
console.log(moment().toISOString(true));
// sample output: 2022-04-06T16:26:36.758+03:00
Use Temporal.
Temporal.Now.zonedDateTimeISO().toString()
// '2022-08-09T14:16:47.762797591-07:00[America/Los_Angeles]'
To omit the fractional seconds and IANA time zone:
Temporal.Now.zonedDateTimeISO().toString({
timeZoneName: "never",
fractionalSecondDigits: 0
})
// '2022-08-09T14:18:34-07:00'
Note: Temporal is currently (2022) available as a polyfill, but will soon be available in major browsers.
With luxon:
DateTime.now().toISODate() // 2022-05-23
Here are the functions I used for this end:
function localToGMTStingTime(localTime = null) {
var date = localTime ? new Date(localTime) : new Date();
return new Date(date.getTime() + (date.getTimezoneOffset() * 60000)).toISOString();
};
function GMTToLocalStingTime(GMTTime = null) {
var date = GMTTime ? new Date(GMTTime) : new Date();;
return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString();
};
let myDate = new Date(dateToBeFormatted * 1000); // depends if you have milliseconds, or seconds, then the * 1000 might be not, or required.
timeOffset = myDate.getTimezoneOffset();
myDate = new Date(myDate.getTime() - (timeOffset * 60 * 1000));
console.log(myDate.toISOString().split('T')[0]);
Inspired by https://stackoverflow.com/a/29774197/11127383, including timezone offset comment.
a simple way to get:
//using a sample date
let iso_str = '2022-06-11T01:51:59.618Z';
let d = new Date(iso_str);
let tz = 'America/Santiago'
let options = {
timeZone:tz ,
timeZoneName:'longOffset',
year: 'numeric',
month: 'numeric',
day: 'numeric',
hour: 'numeric',
minute: 'numeric',
second: 'numeric',
fractionalSecondDigits: 3
}
str_locale = d.toLocaleString("sv-SE",options);
iso_str_tz = str_locale.replace(/(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2}),(\d+)\s+/,'$1-$2-$3T$4:$5:$6.$7').replace('GMT−', '-' ).replace('GMT+','+')
console.log('iso_str : ',iso_str);
console.log('str_locale : ',str_locale);
console.log('iso_str_tz : ',iso_str_tz);
console.log('iso_str_tz --> date : ',new Date(iso_str_tz));
console.log('iso_str_tz --> iso_str: ',new Date(iso_str_tz).toISOString());
Using moment.js, you can use keepOffset parameter of toISOString:
toISOString(keepOffset?: boolean): string;
moment().toISOString(true)
Alternative approach with dayjs
import dayjs from "dayjs"
const formattedDateTime = dayjs(new Date()).format()
console.log(formattedDateTime) // Prints 2022-11-09T07:49:29+03:00
Here's another way a convert your date with an offset.
function toCustomDateString(date, offset) {
function pad(number) {
if (number < 10) {
return "0" + number;
}
return number;
}
var offsetHours = offset / 60;
var offsetMinutes = offset % 60;
var sign = (offset > 0) ? "+" : "-";
offsetHours = pad(Math.floor(Math.abs(offsetHours)));
offsetMinutes = pad(Math.abs(offsetMinutes));
return date.getFullYear() +
"-" + pad(date.getMonth() + 1) +
"-" + pad(date.getDate()) +
"T" + pad(date.getHours()) +
":" + pad(date.getMinutes()) +
":" + pad(date.getSeconds()) +
sign + offsetHours +
":" + offsetMinutes;
}
Then you can use it like this:
var date = new Date();
var offset = 330; // offset in minutes from UTC, for India it is 330 minutes ahead of UTC
var customDateString = toCustomDateString(date, offset);
console.log(customDateString);
// Output: "2023-02-09T10:29:31+05:30"
function setDate(){
var now = new Date();
now.setMinutes(now.getMinutes() - now.getTimezoneOffset());
var timeToSet = now.toISOString().slice(0,16);
/*
If you have an element called "eventDate" like the following:
<input type="datetime-local" name="eventdate" id="eventdate" />
and you would like to set the current and minimum time then use the following:
*/
var elem = document.getElementById("eventDate");
elem.value = timeToSet;
elem.min = timeToSet;
}
I found another more easy solution:
let now = new Date();
// correct time zone offset for generating iso string
now.setMinutes(now.getMinutes() - now.getTimezoneOffset())
now = now.toISOString();
I undo the timezone offset by substracting it from the current date object.
The UTC time from the date object is now pointing to the local time.
That gives you the possibility to get the iso date for the local time.
Goal: Find the local time and UTC time offset then construct the URL in following format.
Example URL: /Actions/Sleep?duration=2002-10-10T12:00:00−05:00
The format is based on the W3C recommendation. The documentation says:
For example, 2002-10-10T12:00:00−05:00 (noon on 10 October 2002,
Central Daylight Savings Time as well as Eastern Standard Time in the U.S.)
is equal to 2002-10-10T17:00:00Z, five hours later than 2002-10-10T12:00:00Z.
So based on my understanding, I need to find my local time by new Date() then use getTimezoneOffset() function to compute the difference then attach it to the end of string.
Get local time with format
var local = new Date().format("yyyy-MM-ddThh:mm:ss"); // 2013-07-02T09:00:00
Get UTC time offset by hour
var offset = local.getTimezoneOffset() / 60; // 7
Construct URL (time part only)
var duration = local + "-" + offset + ":00"; // 2013-07-02T09:00:00-7:00
The above output means my local time is 2013/07/02 9am and difference from UTC is 7 hours (UTC is 7 hours ahead of local time)
So far it seems to work but what if getTimezoneOffset() returns negative value like -120?
I'm wondering how the format should look like in such case because I cannot figure out from W3C documentation.
Here's a simple helper function that will format JS dates for you.
function toIsoString(date) {
var tzo = -date.getTimezoneOffset(),
dif = tzo >= 0 ? '+' : '-',
pad = function(num) {
return (num < 10 ? '0' : '') + num;
};
return date.getFullYear() +
'-' + pad(date.getMonth() + 1) +
'-' + pad(date.getDate()) +
'T' + pad(date.getHours()) +
':' + pad(date.getMinutes()) +
':' + pad(date.getSeconds()) +
dif + pad(Math.floor(Math.abs(tzo) / 60)) +
':' + pad(Math.abs(tzo) % 60);
}
var dt = new Date();
console.log(toIsoString(dt));
getTimezoneOffset() returns the opposite sign of the format required by the spec that you referenced.
This format is also known as ISO8601, or more precisely as RFC3339.
In this format, UTC is represented with a Z while all other formats are represented by an offset from UTC. The meaning is the same as JavaScript's, but the order of subtraction is inverted, so the result carries the opposite sign.
Also, there is no method on the native Date object called format, so your function in #1 will fail unless you are using a library to achieve this. Refer to this documentation.
If you are seeking a library that can work with this format directly, I recommend trying moment.js. In fact, this is the default format, so you can simply do this:
var m = moment(); // get "now" as a moment
var s = m.format(); // the ISO format is the default so no parameters are needed
// sample output: 2013-07-01T17:55:13-07:00
This is a well-tested, cross-browser solution, and has many other useful features.
I think it is worth considering that you can get the requested info with just a single API call to the standard library...
new Date().toLocaleString( 'sv', { timeZoneName: 'short' } );
// produces "2019-10-30 15:33:47 GMT−4"
You would have to do text swapping if you want to add the 'T' delimiter, remove the 'GMT-', or append the ':00' to the end.
But then you can easily play with the other options if you want to eg. use 12h time or omit the seconds etc.
Note that I'm using Sweden as locale because it is one of the countries that uses ISO 8601 format. I think most of the ISO countries use this 'GMT-4' format for the timezone offset other then Canada which uses the time zone abbreviation eg. "EDT" for eastern-daylight-time.
You can get the same thing from the newer standard i18n function "Intl.DateTimeFormat()"
but you have to tell it to include the time via the options or it will just give date.
My answer is a slight variation for those who just want today's date in the local timezone in the YYYY-MM-DD format.
Let me be clear:
My Goal: get today's date in the user's timezone but formatted as ISO8601 (YYYY-MM-DD)
Here is the code:
new Date().toLocaleDateString("sv") // "2020-02-23" //
This works because the Sweden locale uses the ISO 8601 format.
This is my function for the clients timezone, it's lite weight and simple
function getCurrentDateTimeMySql() {
var tzoffset = (new Date()).getTimezoneOffset() * 60000; //offset in milliseconds
var localISOTime = (new Date(Date.now() - tzoffset)).toISOString().slice(0, 19).replace('T', ' ');
var mySqlDT = localISOTime;
return mySqlDT;
}
Check this:
function dateToLocalISO(date) {
const off = date.getTimezoneOffset()
const absoff = Math.abs(off)
return (new Date(date.getTime() - off*60*1000).toISOString().substr(0,23) +
(off > 0 ? '-' : '+') +
Math.floor(absoff / 60).toFixed(0).padStart(2,'0') + ':' +
(absoff % 60).toString().padStart(2,'0'))
}
// Test it:
d = new Date()
dateToLocalISO(d)
// ==> '2019-06-21T16:07:22.181-03:00'
// Is similar to:
moment = require('moment')
moment(d).format('YYYY-MM-DDTHH:mm:ss.SSSZ')
// ==> '2019-06-21T16:07:22.181-03:00'
You can achieve this with a few simple extension methods. The following Date extension method returns just the timezone component in ISO format, then you can define another for the date/time part and combine them for a complete date-time-offset string.
Date.prototype.getISOTimezoneOffset = function () {
const offset = this.getTimezoneOffset();
return (offset < 0 ? "+" : "-") + Math.floor(Math.abs(offset / 60)).leftPad(2) + ":" + (Math.abs(offset % 60)).leftPad(2);
}
Date.prototype.toISOLocaleString = function () {
return this.getFullYear() + "-" + (this.getMonth() + 1).leftPad(2) + "-" +
this.getDate().leftPad(2) + "T" + this.getHours().leftPad(2) + ":" +
this.getMinutes().leftPad(2) + ":" + this.getSeconds().leftPad(2) + "." +
this.getMilliseconds().leftPad(3);
}
Number.prototype.leftPad = function (size) {
var s = String(this);
while (s.length < (size || 2)) {
s = "0" + s;
}
return s;
}
Example usage:
var date = new Date();
console.log(date.toISOLocaleString() + date.getISOTimezoneOffset());
// Prints "2020-08-05T16:15:46.525+10:00"
I know it's 2020 and most people are probably using Moment.js by now, but a simple copy & pastable solution is still sometimes handy to have.
(The reason I split the date/time and offset methods is because I'm using an old Datejs library which already provides a flexible toString method with custom format specifiers, but just doesn't include the timezone offset. Hence, I added toISOLocaleString for anyone without said library.)
Just my two cents here
I was facing this issue with datetimes so what I did is this:
const moment = require('moment-timezone')
const date = moment.tz('America/Bogota').format()
Then save date to db to be able to compare it from some query.
To install moment-timezone
npm i moment-timezone
No moment.js needed: Here's a full round trip answer, from an input type of "datetime-local" which outputs an ISOLocal string to UTCseconds at GMT and back:
<input type="datetime-local" value="2020-02-16T19:30">
isoLocal="2020-02-16T19:30"
utcSeconds=new Date(isoLocal).getTime()/1000
//here you have 1581899400 for utcSeconds
let isoLocal=new Date(utcSeconds*1000-new Date().getTimezoneOffset()*60000).toISOString().substring(0,16)
2020-02-16T19:30
date to ISO string,
with local(computer) time zone,
with or without milliseconds
ISO ref: https://en.wikipedia.org/wiki/ISO_8601
how to use: toIsoLocalTime(new Date())
function toIsoLocalTime(value) {
if (value instanceof Date === false)
value = new Date();
const off = value.getTimezoneOffset() * -1;
const del = value.getMilliseconds() ? 'Z' : '.'; // have milliseconds ?
value = new Date(value.getTime() + off * 60000); // add or subtract time zone
return value
.toISOString()
.split(del)[0]
+ (off < 0 ? '-' : '+')
+ ('0' + Math.abs(Math.floor(off / 60))).substr(-2)
+ ':'
+ ('0' + Math.abs(off % 60)).substr(-2);
}
function test(value) {
const event = new Date(value);
console.info(value + ' -> ' + toIsoLocalTime(event) + ', test = ' + (event.getTime() === (new Date(toIsoLocalTime(event))).getTime() ));
}
test('2017-06-14T10:00:00+03:00'); // test with timezone
test('2017-06-14T10:00:00'); // test with local timezone
test('2017-06-14T10:00:00Z'); // test with UTC format
test('2099-12-31T23:59:59.999Z'); // date with milliseconds
test((new Date()).toString()); // now
consider using moment (like Matt's answer).
From version 2.20.0, you may call .toISOString(true) to prevent UTC conversion:
console.log(moment().toISOString(true));
// sample output: 2022-04-06T16:26:36.758+03:00
Use Temporal.
Temporal.Now.zonedDateTimeISO().toString()
// '2022-08-09T14:16:47.762797591-07:00[America/Los_Angeles]'
To omit the fractional seconds and IANA time zone:
Temporal.Now.zonedDateTimeISO().toString({
timeZoneName: "never",
fractionalSecondDigits: 0
})
// '2022-08-09T14:18:34-07:00'
Note: Temporal is currently (2022) available as a polyfill, but will soon be available in major browsers.
With luxon:
DateTime.now().toISODate() // 2022-05-23
Here are the functions I used for this end:
function localToGMTStingTime(localTime = null) {
var date = localTime ? new Date(localTime) : new Date();
return new Date(date.getTime() + (date.getTimezoneOffset() * 60000)).toISOString();
};
function GMTToLocalStingTime(GMTTime = null) {
var date = GMTTime ? new Date(GMTTime) : new Date();;
return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString();
};
let myDate = new Date(dateToBeFormatted * 1000); // depends if you have milliseconds, or seconds, then the * 1000 might be not, or required.
timeOffset = myDate.getTimezoneOffset();
myDate = new Date(myDate.getTime() - (timeOffset * 60 * 1000));
console.log(myDate.toISOString().split('T')[0]);
Inspired by https://stackoverflow.com/a/29774197/11127383, including timezone offset comment.
a simple way to get:
//using a sample date
let iso_str = '2022-06-11T01:51:59.618Z';
let d = new Date(iso_str);
let tz = 'America/Santiago'
let options = {
timeZone:tz ,
timeZoneName:'longOffset',
year: 'numeric',
month: 'numeric',
day: 'numeric',
hour: 'numeric',
minute: 'numeric',
second: 'numeric',
fractionalSecondDigits: 3
}
str_locale = d.toLocaleString("sv-SE",options);
iso_str_tz = str_locale.replace(/(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2}),(\d+)\s+/,'$1-$2-$3T$4:$5:$6.$7').replace('GMT−', '-' ).replace('GMT+','+')
console.log('iso_str : ',iso_str);
console.log('str_locale : ',str_locale);
console.log('iso_str_tz : ',iso_str_tz);
console.log('iso_str_tz --> date : ',new Date(iso_str_tz));
console.log('iso_str_tz --> iso_str: ',new Date(iso_str_tz).toISOString());
Using moment.js, you can use keepOffset parameter of toISOString:
toISOString(keepOffset?: boolean): string;
moment().toISOString(true)
Alternative approach with dayjs
import dayjs from "dayjs"
const formattedDateTime = dayjs(new Date()).format()
console.log(formattedDateTime) // Prints 2022-11-09T07:49:29+03:00
Here's another way a convert your date with an offset.
function toCustomDateString(date, offset) {
function pad(number) {
if (number < 10) {
return "0" + number;
}
return number;
}
var offsetHours = offset / 60;
var offsetMinutes = offset % 60;
var sign = (offset > 0) ? "+" : "-";
offsetHours = pad(Math.floor(Math.abs(offsetHours)));
offsetMinutes = pad(Math.abs(offsetMinutes));
return date.getFullYear() +
"-" + pad(date.getMonth() + 1) +
"-" + pad(date.getDate()) +
"T" + pad(date.getHours()) +
":" + pad(date.getMinutes()) +
":" + pad(date.getSeconds()) +
sign + offsetHours +
":" + offsetMinutes;
}
Then you can use it like this:
var date = new Date();
var offset = 330; // offset in minutes from UTC, for India it is 330 minutes ahead of UTC
var customDateString = toCustomDateString(date, offset);
console.log(customDateString);
// Output: "2023-02-09T10:29:31+05:30"
function setDate(){
var now = new Date();
now.setMinutes(now.getMinutes() - now.getTimezoneOffset());
var timeToSet = now.toISOString().slice(0,16);
/*
If you have an element called "eventDate" like the following:
<input type="datetime-local" name="eventdate" id="eventdate" />
and you would like to set the current and minimum time then use the following:
*/
var elem = document.getElementById("eventDate");
elem.value = timeToSet;
elem.min = timeToSet;
}
I found another more easy solution:
let now = new Date();
// correct time zone offset for generating iso string
now.setMinutes(now.getMinutes() - now.getTimezoneOffset())
now = now.toISOString();
I undo the timezone offset by substracting it from the current date object.
The UTC time from the date object is now pointing to the local time.
That gives you the possibility to get the iso date for the local time.
Let's say we have this datetime:
var d = new Date("Sat Jul 21 2018 14:00:00 GMT+0200");
Exporting it as a string (console.log(d)) gives inconsistent results among browsers:
Sat Jul 21 2018 14:00:00 GMT+0200 (Paris, Madrid (heure d’été)) with Chrome
Sat Jul 21 14:00:00 UTC+0200 2018 with Internet Explorer, etc.
so we can't send datetime to a server with an unconsistent format.
The natural idea then would be to ask for an ISO8601 datetime, and use d.toISOString(); but it gives the UTC datetime: 2018-07-21T12:00:00.000Z whereas I would like the local-timezone time instead:
2018-07-21T14:00:00+0200
or
2018-07-21T14:00:00
How to get this (without relying on a third party dependency like momentjs)?
I tried this, which seems to work, but isn't there a more natural way to do it?
var pad = function(i) { return (i < 10) ? '0' + i : i; };
var d = new Date("Sat Jul 21 2018 14:00:00 GMT+0200");
Y = d.getFullYear();
m = d.getMonth() + 1;
D = d.getDate();
H = d.getHours();
M = d.getMinutes();
S = d.getSeconds();
s = Y + '-' + pad(m) + '-' + pad(D) + 'T' + pad(H) + ':' + pad(M) + ':' + pad(S);
console.log(s);
There is limited built-in support for formatting date strings with timezones in ECMA-262, there is either implementation dependent toString and toLocaleString methods or toISOString, which is always UTC. It would be good if toISOString allowed a parameter to specify UTC or local offset (where the default is UTC).
Writing your own function to generate an ISO 8601 compliant timestamp with local offset isn't difficult:
function toISOLocal(d) {
var z = n => ('0' + n).slice(-2);
var zz = n => ('00' + n).slice(-3);
var off = d.getTimezoneOffset();
var sign = off > 0? '-' : '+';
off = Math.abs(off);
return d.getFullYear() + '-'
+ z(d.getMonth()+1) + '-' +
z(d.getDate()) + 'T' +
z(d.getHours()) + ':' +
z(d.getMinutes()) + ':' +
z(d.getSeconds()) + '.' +
zz(d.getMilliseconds()) +
sign + z(off/60|0) + ':' + z(off%60);
}
console.log(toISOLocal(new Date()));
The trick is to adjust the time by the timezone, and then use toISOString(). You can do this by creating a new date with the original time and subtracting by the timezone offssetfrom the original time:
var d = new Date("Sat Jul 21 2018 14:00:00 GMT+0200");
var newd = new Date(d.getTime() - d.getTimezoneOffset()*60000);
console.log(newd.toISOString()); // 2018-07-21T22:00:00.000Z
Alternatively, you can simply adjust the original date variable:
var d = new Date("Sat Jul 21 2018 14:00:00 GMT+0200");
d = new Date(d.getTime() - d.getTimezoneOffset()*60000);
console.log(d.toISOString()); // 2018-07-21T22:00:00.000Z
For your convenience, the result from .getTime() is the number of milliseconds since 1 January 1970. However, getTimezoneOffset() gives a time zone difference from UTC in minutes; that’s why you need to multiply by 60000 to get this in milliseconds.
Of course, the new time is still relative to UTC, so you’ll have to ignore the Z at the end:
d = d.slice(0,-1); // 2018-07-21T22:00:00.000
My version:
// https://stackoverflow.com/questions/10830357/javascript-toisostring-ignores-timezone-offset/37661393#37661393
// https://stackoverflow.com/questions/49330139/date-toisostring-but-local-time-instead-of-utc/49332027#49332027
function toISOLocal(d) {
const z = n => ('0' + n).slice(-2);
let off = d.getTimezoneOffset();
const sign = off < 0 ? '+' : '-';
off = Math.abs(off);
return new Date(d.getTime() - (d.getTimezoneOffset() * 60000)).toISOString().slice(0, -1) + sign + z(off / 60 | 0) + ':' + z(off % 60);
}
console.log(toISOLocal(new Date()));
i have found a solution which has worked for me.
see this post: Modifying an ISO Date in Javascript
for myself i tested this with slight modification to remove the "T", and it is working. here is the code i am using:
// Create date at UMT-0
var date = new Date();
// Modify the UMT + 2 hours
date.setHours(date.getHours() + 2);
// Reformat the timestamp without the "T", as YYYY-MM-DD hh:mm:ss
var timestamp = date.toISOString().replace("T", " ").split(".")[0];
and an alternative method is stipulate the format you need, like this:
// Create the timestamp format
var timeStamp = Utilities.formatDate(new Date(), "GMT+2", "yyyy-MM-dd' 'HH:mm:ss");
note: these are suitable in locations that do not have daylight saving changes to the time during the year
it has been pointed out that the above formulas are for a specific timezone.
in order to have the local time in ISO format, first specify suitable Locale ("sv-SE" is the closest and easiest to modify), then make modification (change the space to a T) to be same as ISO format. like this:
var date = new Date(); // Create date
var timestamp = date.toLocaleString("sv-SE").replace(" ", "T").split(".")[0]; // Reformat the Locale timestamp ISO YYYY-MM-DDThh:mm:ss
References:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString)
https://www.w3schools.com/Jsref/jsref_tolocalestring.asp
https://www.w3schools.com/Jsref/tryit.asp?filename=tryjsref_tolocalestring_date_all
Goal: Find the local time and UTC time offset then construct the URL in following format.
Example URL: /Actions/Sleep?duration=2002-10-10T12:00:00−05:00
The format is based on the W3C recommendation. The documentation says:
For example, 2002-10-10T12:00:00−05:00 (noon on 10 October 2002,
Central Daylight Savings Time as well as Eastern Standard Time in the U.S.)
is equal to 2002-10-10T17:00:00Z, five hours later than 2002-10-10T12:00:00Z.
So based on my understanding, I need to find my local time by new Date() then use getTimezoneOffset() function to compute the difference then attach it to the end of string.
Get local time with format
var local = new Date().format("yyyy-MM-ddThh:mm:ss"); // 2013-07-02T09:00:00
Get UTC time offset by hour
var offset = local.getTimezoneOffset() / 60; // 7
Construct URL (time part only)
var duration = local + "-" + offset + ":00"; // 2013-07-02T09:00:00-7:00
The above output means my local time is 2013/07/02 9am and difference from UTC is 7 hours (UTC is 7 hours ahead of local time)
So far it seems to work but what if getTimezoneOffset() returns negative value like -120?
I'm wondering how the format should look like in such case because I cannot figure out from W3C documentation.
Here's a simple helper function that will format JS dates for you.
function toIsoString(date) {
var tzo = -date.getTimezoneOffset(),
dif = tzo >= 0 ? '+' : '-',
pad = function(num) {
return (num < 10 ? '0' : '') + num;
};
return date.getFullYear() +
'-' + pad(date.getMonth() + 1) +
'-' + pad(date.getDate()) +
'T' + pad(date.getHours()) +
':' + pad(date.getMinutes()) +
':' + pad(date.getSeconds()) +
dif + pad(Math.floor(Math.abs(tzo) / 60)) +
':' + pad(Math.abs(tzo) % 60);
}
var dt = new Date();
console.log(toIsoString(dt));
getTimezoneOffset() returns the opposite sign of the format required by the spec that you referenced.
This format is also known as ISO8601, or more precisely as RFC3339.
In this format, UTC is represented with a Z while all other formats are represented by an offset from UTC. The meaning is the same as JavaScript's, but the order of subtraction is inverted, so the result carries the opposite sign.
Also, there is no method on the native Date object called format, so your function in #1 will fail unless you are using a library to achieve this. Refer to this documentation.
If you are seeking a library that can work with this format directly, I recommend trying moment.js. In fact, this is the default format, so you can simply do this:
var m = moment(); // get "now" as a moment
var s = m.format(); // the ISO format is the default so no parameters are needed
// sample output: 2013-07-01T17:55:13-07:00
This is a well-tested, cross-browser solution, and has many other useful features.
I think it is worth considering that you can get the requested info with just a single API call to the standard library...
new Date().toLocaleString( 'sv', { timeZoneName: 'short' } );
// produces "2019-10-30 15:33:47 GMT−4"
You would have to do text swapping if you want to add the 'T' delimiter, remove the 'GMT-', or append the ':00' to the end.
But then you can easily play with the other options if you want to eg. use 12h time or omit the seconds etc.
Note that I'm using Sweden as locale because it is one of the countries that uses ISO 8601 format. I think most of the ISO countries use this 'GMT-4' format for the timezone offset other then Canada which uses the time zone abbreviation eg. "EDT" for eastern-daylight-time.
You can get the same thing from the newer standard i18n function "Intl.DateTimeFormat()"
but you have to tell it to include the time via the options or it will just give date.
My answer is a slight variation for those who just want today's date in the local timezone in the YYYY-MM-DD format.
Let me be clear:
My Goal: get today's date in the user's timezone but formatted as ISO8601 (YYYY-MM-DD)
Here is the code:
new Date().toLocaleDateString("sv") // "2020-02-23" //
This works because the Sweden locale uses the ISO 8601 format.
This is my function for the clients timezone, it's lite weight and simple
function getCurrentDateTimeMySql() {
var tzoffset = (new Date()).getTimezoneOffset() * 60000; //offset in milliseconds
var localISOTime = (new Date(Date.now() - tzoffset)).toISOString().slice(0, 19).replace('T', ' ');
var mySqlDT = localISOTime;
return mySqlDT;
}
Check this:
function dateToLocalISO(date) {
const off = date.getTimezoneOffset()
const absoff = Math.abs(off)
return (new Date(date.getTime() - off*60*1000).toISOString().substr(0,23) +
(off > 0 ? '-' : '+') +
Math.floor(absoff / 60).toFixed(0).padStart(2,'0') + ':' +
(absoff % 60).toString().padStart(2,'0'))
}
// Test it:
d = new Date()
dateToLocalISO(d)
// ==> '2019-06-21T16:07:22.181-03:00'
// Is similar to:
moment = require('moment')
moment(d).format('YYYY-MM-DDTHH:mm:ss.SSSZ')
// ==> '2019-06-21T16:07:22.181-03:00'
You can achieve this with a few simple extension methods. The following Date extension method returns just the timezone component in ISO format, then you can define another for the date/time part and combine them for a complete date-time-offset string.
Date.prototype.getISOTimezoneOffset = function () {
const offset = this.getTimezoneOffset();
return (offset < 0 ? "+" : "-") + Math.floor(Math.abs(offset / 60)).leftPad(2) + ":" + (Math.abs(offset % 60)).leftPad(2);
}
Date.prototype.toISOLocaleString = function () {
return this.getFullYear() + "-" + (this.getMonth() + 1).leftPad(2) + "-" +
this.getDate().leftPad(2) + "T" + this.getHours().leftPad(2) + ":" +
this.getMinutes().leftPad(2) + ":" + this.getSeconds().leftPad(2) + "." +
this.getMilliseconds().leftPad(3);
}
Number.prototype.leftPad = function (size) {
var s = String(this);
while (s.length < (size || 2)) {
s = "0" + s;
}
return s;
}
Example usage:
var date = new Date();
console.log(date.toISOLocaleString() + date.getISOTimezoneOffset());
// Prints "2020-08-05T16:15:46.525+10:00"
I know it's 2020 and most people are probably using Moment.js by now, but a simple copy & pastable solution is still sometimes handy to have.
(The reason I split the date/time and offset methods is because I'm using an old Datejs library which already provides a flexible toString method with custom format specifiers, but just doesn't include the timezone offset. Hence, I added toISOLocaleString for anyone without said library.)
Just my two cents here
I was facing this issue with datetimes so what I did is this:
const moment = require('moment-timezone')
const date = moment.tz('America/Bogota').format()
Then save date to db to be able to compare it from some query.
To install moment-timezone
npm i moment-timezone
No moment.js needed: Here's a full round trip answer, from an input type of "datetime-local" which outputs an ISOLocal string to UTCseconds at GMT and back:
<input type="datetime-local" value="2020-02-16T19:30">
isoLocal="2020-02-16T19:30"
utcSeconds=new Date(isoLocal).getTime()/1000
//here you have 1581899400 for utcSeconds
let isoLocal=new Date(utcSeconds*1000-new Date().getTimezoneOffset()*60000).toISOString().substring(0,16)
2020-02-16T19:30
date to ISO string,
with local(computer) time zone,
with or without milliseconds
ISO ref: https://en.wikipedia.org/wiki/ISO_8601
how to use: toIsoLocalTime(new Date())
function toIsoLocalTime(value) {
if (value instanceof Date === false)
value = new Date();
const off = value.getTimezoneOffset() * -1;
const del = value.getMilliseconds() ? 'Z' : '.'; // have milliseconds ?
value = new Date(value.getTime() + off * 60000); // add or subtract time zone
return value
.toISOString()
.split(del)[0]
+ (off < 0 ? '-' : '+')
+ ('0' + Math.abs(Math.floor(off / 60))).substr(-2)
+ ':'
+ ('0' + Math.abs(off % 60)).substr(-2);
}
function test(value) {
const event = new Date(value);
console.info(value + ' -> ' + toIsoLocalTime(event) + ', test = ' + (event.getTime() === (new Date(toIsoLocalTime(event))).getTime() ));
}
test('2017-06-14T10:00:00+03:00'); // test with timezone
test('2017-06-14T10:00:00'); // test with local timezone
test('2017-06-14T10:00:00Z'); // test with UTC format
test('2099-12-31T23:59:59.999Z'); // date with milliseconds
test((new Date()).toString()); // now
consider using moment (like Matt's answer).
From version 2.20.0, you may call .toISOString(true) to prevent UTC conversion:
console.log(moment().toISOString(true));
// sample output: 2022-04-06T16:26:36.758+03:00
Use Temporal.
Temporal.Now.zonedDateTimeISO().toString()
// '2022-08-09T14:16:47.762797591-07:00[America/Los_Angeles]'
To omit the fractional seconds and IANA time zone:
Temporal.Now.zonedDateTimeISO().toString({
timeZoneName: "never",
fractionalSecondDigits: 0
})
// '2022-08-09T14:18:34-07:00'
Note: Temporal is currently (2022) available as a polyfill, but will soon be available in major browsers.
With luxon:
DateTime.now().toISODate() // 2022-05-23
Here are the functions I used for this end:
function localToGMTStingTime(localTime = null) {
var date = localTime ? new Date(localTime) : new Date();
return new Date(date.getTime() + (date.getTimezoneOffset() * 60000)).toISOString();
};
function GMTToLocalStingTime(GMTTime = null) {
var date = GMTTime ? new Date(GMTTime) : new Date();;
return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString();
};
let myDate = new Date(dateToBeFormatted * 1000); // depends if you have milliseconds, or seconds, then the * 1000 might be not, or required.
timeOffset = myDate.getTimezoneOffset();
myDate = new Date(myDate.getTime() - (timeOffset * 60 * 1000));
console.log(myDate.toISOString().split('T')[0]);
Inspired by https://stackoverflow.com/a/29774197/11127383, including timezone offset comment.
a simple way to get:
//using a sample date
let iso_str = '2022-06-11T01:51:59.618Z';
let d = new Date(iso_str);
let tz = 'America/Santiago'
let options = {
timeZone:tz ,
timeZoneName:'longOffset',
year: 'numeric',
month: 'numeric',
day: 'numeric',
hour: 'numeric',
minute: 'numeric',
second: 'numeric',
fractionalSecondDigits: 3
}
str_locale = d.toLocaleString("sv-SE",options);
iso_str_tz = str_locale.replace(/(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2}),(\d+)\s+/,'$1-$2-$3T$4:$5:$6.$7').replace('GMT−', '-' ).replace('GMT+','+')
console.log('iso_str : ',iso_str);
console.log('str_locale : ',str_locale);
console.log('iso_str_tz : ',iso_str_tz);
console.log('iso_str_tz --> date : ',new Date(iso_str_tz));
console.log('iso_str_tz --> iso_str: ',new Date(iso_str_tz).toISOString());
Using moment.js, you can use keepOffset parameter of toISOString:
toISOString(keepOffset?: boolean): string;
moment().toISOString(true)
Alternative approach with dayjs
import dayjs from "dayjs"
const formattedDateTime = dayjs(new Date()).format()
console.log(formattedDateTime) // Prints 2022-11-09T07:49:29+03:00
Here's another way a convert your date with an offset.
function toCustomDateString(date, offset) {
function pad(number) {
if (number < 10) {
return "0" + number;
}
return number;
}
var offsetHours = offset / 60;
var offsetMinutes = offset % 60;
var sign = (offset > 0) ? "+" : "-";
offsetHours = pad(Math.floor(Math.abs(offsetHours)));
offsetMinutes = pad(Math.abs(offsetMinutes));
return date.getFullYear() +
"-" + pad(date.getMonth() + 1) +
"-" + pad(date.getDate()) +
"T" + pad(date.getHours()) +
":" + pad(date.getMinutes()) +
":" + pad(date.getSeconds()) +
sign + offsetHours +
":" + offsetMinutes;
}
Then you can use it like this:
var date = new Date();
var offset = 330; // offset in minutes from UTC, for India it is 330 minutes ahead of UTC
var customDateString = toCustomDateString(date, offset);
console.log(customDateString);
// Output: "2023-02-09T10:29:31+05:30"
function setDate(){
var now = new Date();
now.setMinutes(now.getMinutes() - now.getTimezoneOffset());
var timeToSet = now.toISOString().slice(0,16);
/*
If you have an element called "eventDate" like the following:
<input type="datetime-local" name="eventdate" id="eventdate" />
and you would like to set the current and minimum time then use the following:
*/
var elem = document.getElementById("eventDate");
elem.value = timeToSet;
elem.min = timeToSet;
}
I found another more easy solution:
let now = new Date();
// correct time zone offset for generating iso string
now.setMinutes(now.getMinutes() - now.getTimezoneOffset())
now = now.toISOString();
I undo the timezone offset by substracting it from the current date object.
The UTC time from the date object is now pointing to the local time.
That gives you the possibility to get the iso date for the local time.