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.
I would like to generate in JS a Date object (or XDate) starting from a UTC unix timestamp, add a timezone offset and then generate a String in the format "yyyy-MM-dd HH:mm:ss".
For now I did this:
createServerRelativeTs : function(unixtimeutc, utcoffset) {
var stimeUTCoffset = (isNaN(utcoffset)) ? 1 : utcoffset;
var time = new XDate(Math.round(unixtimeutc * 1000));
var hours = time.getUTCHours() + stimeUTCoffset;
time.setUTCHours(hours);
return time.toString("yyyy-MM-dd HH:mm:ss");
}
in which utcoffset is a integer number and unixtimeutc is a unixtimestamp
The problem with this code is that If I change the timezone in my OS the result changes! If I add the offset value to the timestamp it gets ignored. How can I get a OS-timezone-independent result?
This is really a combination of a few answers. You need to work in UTC to avoid the effects of the host timezone which is considered when using non-UTC methods.
So create a Date from the UNIX time value, adjust the UTC minutes for the offset, then format the output string using UTC methods as local.
This might be a bit simpler with a library, but it's not really necessary.
/* Given a Date, return a string in //yyyy-MM-dd HH:mm:ss format
** #param {Date} d
** #returns {string}
*/
function formatISOLocal(d) {
function z(n){return (n<10?'0':'')+n}
if (isNaN(d)) return d.toString();
return d.getUTCFullYear() + '-' +
z(d.getUTCMonth() + 1) + '-' +
z(d.getUTCDate()) + ' ' +
z(d.getUTCHours()) + ':' +
z(d.getUTCMinutes()) + ':' +
z(d.getUTCSeconds()) ;
}
/* Adjust time value for provided timezone
** #param {Date} d - date object
** #param {string} tz - UTC offset as +/-HH:MM or +/-HHMM
** #returns {Date}
*/
function adjustForTimezone(d, tz) {
var sign = /^-/.test(tz)? -1 : 1;
var b = tz.match(/\d\d/g); // should do some validation here
var offset = (b[0]*60 + +b[1]) * sign;
d.setUTCMinutes(d.getUTCMinutes() + offset);
return d;
}
// Given a UNIX time value for 1 Jan 2017 00:00:00,
// Return a string for the equivalent time in
// UTC+10:00
// 2017-01-01T00:00:00Z seconds
var n = 1483228800;
// Create Date object (a single number value is treated as a UTC time value)
var d = new Date(n * 1000);
// Adjust to UTC+10:00
adjustForTimezone(d, '+10:00');
// Format as local string
console.log(formatISOLocal(d))
I have a string like below
%snd: <00:00:00><00:02:20>
%snd: <00:02:45><00:05:18>
%snd: <00:05:49><00:09:84>
I want to count the time duration between these two tags in each line and show the sum of all the time difference in minutes.Should I have to convert them into proper javascript time object or is there any other direct way I can do it ?
Any help or hint will be highly appreciated.Thank You
If your format is in <minutes:seconds:milliseconds> then pass the string inside <> tags to that function, it will give you time in minutes.Then you can apply your further logic.
function timeToMinutes(time) {
time = time.split(/:/);
return time[0] + (time[1]/60) + time[2]/(60*100);
}
I think it's simpler to avoid Dates altogether. Convert the times to a common denominator, say seconds, do whatever mathematic operations you want on the seconds, then convert back to time at the end.
/* Convert a string in h:mm:ss format to seconds
** #param {string} s - string in hh:mm:ss format
** #returns {number} - time converted to seconds
*/
function parseTime(s) {
var b = s.split(/\D/);
return b[0]*3600 + b[1]*60 + +b[2];
}
/* Convert a time in seconds to hh:mm:ss format
** #param {number} secs - seconds to convert
** #returns {string} - time in hh:mm:ss format
*/
function secondsToTime(secs) {
function z(n){return (n<10?'0':'')+n}
var sign = secs < 0? '-' : '';
secs = Math.abs(secs);
return sign + z(secs / 3600 | 0) + ':' +
z(secs % 3600 / 60 | 0) + ':' +
z(secs % 60);
}
// Get time difference between 00:02:45 and 00:05:18
var diffInSeconds = parseTime('00:05:18') - parseTime('00:02:45');
console.log(secondsToTime(diffInSeconds))
// Deal with -ve difference between 00:05:18 and 00:02:45
var diffInSeconds = parseTime('00:02:45') - parseTime('00:05:18');
console.log(secondsToTime(diffInSeconds))
// Process a time pair (noting that 84 is likely an invalid value but is allowed)
var diff = '<00:05:49><00:09:84>'.match(/\d\d:\d\d:\d\d/g).reduce((a,b)=>secondsToTime(parseTime(b) - parseTime(a)));
console.log(diff);
Let's say I have
a = "2011-11-09 08:00:00"
b = "2011-11-10 08:30:00"
What's the best way of finding how many days, hours, minutes the difference between these two timestamps are in Javascript?
So the output should be "1 day" (ignore the minutes since there is a larger unit (day) in the difference) ?
The only reliable way to convert a string to a date in javascript is to parse it manually. If the format is consistent with what you have posted, then you can convert it to a date as follows:
function stringToDate(s) {
var dateParts = s.split(' ')[0].split('-');
var timeParts = s.split(' ')[1].split(':');
var d = new Date(dateParts[0], --dateParts[1], dateParts[2]);
d.setHours(timeParts[0], timeParts[1], timeParts[2])
return d
}
so you can do:
var a = "2011-11-09 08:00:00"
var b = "2011-11-10 08:30:00"
alert(stringToDate(a) - stringToDate(b));
to get the difference in milliseconds. However, the difference in days between two dates may not be a simple matter of dividing the difference by 8.64e7 (milliseconds in one da). You need to confirm the business logic in regard to that.
EDITED to work in any browser
var matchDate = /(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})/;
var firstDateParsed = matchDate.exec("2011-11-09 08:00:00");
var secondDateParsed = matchDate.exec("2011-11-10 08:30:00");
var a = new Date(firstDateParsed[1], firstDateParsed[2], firstDateParsed[3], firstDateParsed[4], firstDateParsed[5], firstDateParsed[6], 0);
var b = new Date(secondDateParsed[1], secondDateParsed[2], secondDateParsed[3], secondDateParsed[4], secondDateParsed[5], secondDateParsed[6], 0);
var differenceInMilliseconds = a.getTime() - b.getTime();
// minutes
alert(differenceInMilliseconds / 1000 / 60);
// hours
alert(differenceInMilliseconds / 1000 / 60 / 60);
// days
alert(differenceInMilliseconds / 1000 / 60 / 60 / 24);
Tested in IE and Firefox as well as Chrome: http://jsfiddle.net/xkBTS/4/
You'll have to parse the timestamp to a date yourself:
function parseMySQLTimestamp(timestamp) {
var parts = timestamp.match(/^(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})$/);
return new Date(+parts[1], (+parts[2] - 1), +parts[3], +parts[4], +parts[5], +parts[6]);
}
Get the difference in milliseconds by subtracting one date from the other:
var msDifference = parseMySQLTimestamp(b) - parseMySQLTimestamp(a);
Simple arithmetic will let you convert milliseconds to seconds, minutes, or whatever.
By the way, this function will throw an error if a timestamp is passed in that doesn't match the expression. From a software design point of view, this behavior makes sense to me. However, if you want to be able to use that function with strings that may not be in the correct format, you can just do a null check against parts and return null if there is no match.