I have two variables in javascript like:
time: 02:00
date: 25-08-2017
and I'm wondering if I can put these into a Date() object and get the UTC date and time out of it in hours/minutes using getUTCDay(), getUTCHours() and getUTCMinutes() and place them back in the format I got them.
I can load moment.js for it but if I don't have to it would be nice if I can do it without.
Convert your strings to an ISO 8601 string and use it in the Date constructor. From there, you can get whatever data you need
let time = '02:00'
let date = '25-08-2017'
let iso8601Date = date.split('-').reverse().join('-')
let dt = new Date(`${iso8601Date}T${time}`) // will be interpreted as local time
const digitFormatter = new Intl.NumberFormat(undefined, {minimumIntegerDigits: 2})
console.info('Parsed date:', dt)
console.info('UTC date in dd-mm-yyyy:',
`${digitFormatter.format(dt.getUTCDate())}-${(digitFormatter.format(dt.getUTCMonth() + 1))}-${dt.getUTCFullYear()}`
)
console.info('UTC time:', `${digitFormatter.format(dt.getUTCHours())}:${digitFormatter.format(dt.getUTCMinutes())}`)
Related
in a project we are using momentjs with date. And from backend we become the date in the following format: 2016-10-19T08:00:00Z (don't ask me why...)
Now we are setting a new date in frontend from some selectboxes. And I am trying to convert this in the same format:
const date = '25.03.2021';
const hour = '13';
const minute = '45'; // this 3 values come from value of selectboxes
const rawDate = moment(date).hour(hour).minute(minute);
// trying to convert to 2021-03-25T13:45:00Z
rawDate.format(); // output: 2021-03-25T13:45:00+00:00
rawDate.format('DD.MM.YYYY hh:mm:ss'); // output: 03.01.2022 08:00:00
rawDate.format('DD.MM.YYYY hh:mm:ss z'); // output: 03.01.2022 08:00:00 UTC
rawDate.format('DD.MM.YYYY hh:mm:ss Z'); // output: 03.01.2022 08:00:00 +00:00
rawDate.toISOString(); // output: 2022-01-03T08:00:00.000Z
I know I could probably just use format() or toISOString() and slice/replace the last bit. But I like to know is there a way without any string concat/manipulation?
You could use moment.utc() to ensure your date is in UTC, then use .format() with the format string DD-MM-YYYYTHH:mm:ss[Z].
I'd also suggest explicity defining the format you are parsing from in the moment() call, e.g. pass 'DD.MM.YYYY' as the second argument.
The reason the backend takes dates in this format is that it's a standardized way of formatting dates to make them machine-readable and consistent (ISO 8601)
const date = '25.03.2021';
const hour = '13';
const minute = '45';
// Raw date will be in the UTC timezone.
const rawDate = moment(date, 'DD.MM.YYYY').hour(hour).minute(minute).utc();
console.log(rawDate.format('DD-MM-YYYYTHH:mm:ss[Z]'));
<script src="https://momentjs.com/downloads/moment.js"></script>
You can try convert to UTC ..?
i.e. Do you intend to make use of a UTC date/time..?
const date = '2021-03-25';
const hour = '13';
const minute = '45'; // this 3 values come from value of selectboxes
const rawDate = moment(date).hour(hour).minute(minute);
const utc = moment.utc(rawDate);
console.log(rawDate.format('DD.MM.YYYY hh:mm:ss'));
console.log(utc.format()); //2021-03-25T11:45:00Z
I'm trying to calculate the datetime in UTC, i have the bellow code and using Luxon
weeklyDish.orderBeforeTime = timeZoneToUTC(
"Europe/Amsterdam",
year,
month,
day,
hours
);
function timeZoneToUTC(timezone, year, month, day, hours) {
const dateObj = `${year}-${month}-${day} ${hours}:00`;
const datetime = DateTime.fromFormat(dateObj, "yyyy-M-d H:mm", {
zone: timezone,
});
return datetime.toUTC().toString();
}
The code above always return the wrong hour.
How can I get the year, month, hour and return a UTC string to save in the DB?
I'm going to be migrating data that has date as string (example: "2020-12-13"), how can I convert it to UTC date and subtract days correctly?
You need to show an example to demonstrate your issue. The following shows use of Luxon's UTC and setZone methods that both seem to correctly convert a date set for "Europe/Amsterdam".
Note that the string passed to DateTime.fromISO must form a valid ISO 8601 timestamp like YYYY-MM-DDTHH.
let DateTime = luxon.DateTime;
let [tz, y, m, d, h] = ["Europe/Amsterdam", '2020', '11', '30', '12'];
let date = DateTime.fromISO(`${y}-${m}-${d}T${h}`, { zone: "Europe/Amsterdam" });
console.log(tz + '\n' + date.toString());
let dateUTC = date.setZone('UTC');
console.log('setZone to UTC\n' + dateUTC.toString());
let dateUTC2 = date.toUTC();
console.log('toUTC method\n' + dateUTC2.toString());
<script src="https://cdn.jsdelivr.net/npm/luxon#1.25.0/build/global/luxon.min.js"></script>
PS Amsterdam standard time is +1, daylight saving time is +2.
If the date is already parsed, you can use the date constructor directly. However, the constructor depends on the local timezone, luckily you can use Date.UTC instead.
The tricky part is about the timezone, which is not supported in the constructor, but it's a simple addition anyway.
So I'd wager something like so should work:
function timeZoneToUTC(timezone, year, month, day, hours) {
return new Date(Date.UTC(year, month - 1, day, hours + timezone));
}
Note: the month parameter is an index (0-based), so if you have 1=January, you need to decrease your month by one (as in my example).
Edit: uh, apparently, Date.UTC returns a timestamp, so you need to use the constructor anyway.
I'm pulling some data from two different APIs and I want to the objects later on.
However, I'm getting two different date formats: this format "1427457730" and this format "2015-04-10T09:12:22Z". How can I change the format of one of these so I have the same format to work with?
$.each(object, function(index) {
date = object[index].updated_at;
}
Here's one option:
var timestamp = 1427457730;
var date = new Date(timestamp * 1000); // wants milliseconds, not seconds
var dateString = date.toISOString().replace(/\.\d+Z/, 'Z'); // remove the ms
dateString will now be 2015-03-27T12:02:10Z.
Try moment.js
var timestamp = 1427457730;
var date = '2015-04-10T09:12:22Z';
var m1 = moment(timestamp);
var m2 = moment(date);
console.log(m1);
console.log(m2);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.11.1/moment.min.js"></script>
You can use .format() method in moment to parse the date to whatever format you want, just like:
m2.format('YYYY MMM DD ddd HH:mm:ss') // 2015 Apr 10 Fri 17:12:22
Check out the docs for more format tokens.
What you probably want in javascript, are date objects.
The first string is seconds since epoch, javascript needs milliseconds, so multiply it by 1000;
The second string is a valid ISO date, so if the string contains a hyphen just pass it into new Date.
var date = returned_date.indexOf('-') !== -1 ? returned_date : returned_date * 1000;
var date_object = new Date(date);
Making both types into date objects, you could even turn that into a handy function
function format_date(date) {
return new Date(date.indexOf('-') !== -1 ? date : date * 1000);
}
FIDDLE
Take a look at http://momentjs.com/. It is THE date/time formatting library for JavaScript - very simple to use, extremely flexible.
I have something like /Date(1370001284000+0200)/ as timestamp. I guess it is a unix date, isn't it? How can I convert this to a date like this: 31.05.2013 13:54:44
I tried THIS converter for 1370001284 and it gives the right date. So it is in seconds.
But I still get the wrong date for:
var substring = unix_timestamp.replace("/Date(", "");
substring = substring.replace("000+0200)/", "");
var date = new Date();
date.setSeconds(substring);
return date;
Note my use of t.format comes from using Moment.js, it is not part of JavaScript's standard Date prototype.
A Unix timestamp is the number of seconds since 1970-01-01 00:00:00 UTC.
The presence of the +0200 means the numeric string is not a Unix timestamp as it contains timezone adjustment information. You need to handle that separately.
If your timestamp string is in milliseconds, then you can use the milliseconds constructor and Moment.js to format the date into a string:
var t = new Date( 1370001284000 );
var formatted = moment(t).format("dd.mm.yyyy hh:MM:ss");
If your timestamp string is in seconds, then use setSeconds:
var t = new Date();
t.setSeconds( 1370001284 );
var formatted = moment(t).format("dd.mm.yyyy hh:MM:ss");
Looks like you might want the ISO format so that you can retain the timezone.
var dateTime = new Date(1370001284000);
dateTime.toISOString(); // Returns "2013-05-31T11:54:44.000Z"
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString
Without moment.js:
var time_to_show = 1509968436; // unix timestamp in seconds
var t = new Date(time_to_show * 1000);
var formatted = ('0' + t.getHours()).slice(-2) + ':' + ('0' + t.getMinutes()).slice(-2);
document.write(formatted);
The /Date(ms + timezone)/ is a ASP.NET syntax for JSON dates. You might want to use a library like momentjs for parsing such dates. It would come in handy if you need to manipulate or print the dates any time later.
If using react:
import Moment from 'react-moment';
Moment.globalFormat = 'D MMM YYYY';
then:
<td><Moment unix>{1370001284}</Moment></td>
Import moment js:
var fulldate = new Date(1370001284000);
var converted_date = moment(fulldate).format(");
if you're using React I found 'react-moment' library more easy to handle for Front-End related tasks, just import <Moment> component and add unix prop:
import Moment from 'react-moment'
// get date variable
const {date} = this.props
<Moment unix>{date}</Moment>
I would like to add that Using the library momentjs in javascript you can have the whole data information in an object with:
const today = moment(1557697070824.94).toObject();
You should obtain an object with this properties:
today: {
date: 15,
hours: 2,
milliseconds: 207,
minutes: 31,
months: 4
seconds: 22,
years: 2019
}
It is very useful when you have to calculate dates.
for people as dumb as myself, my date was in linux epoch
but it was a string instead of an integer, and that's why i was getting
RangeError: Date value out of bounds
so if you are getting the epoch from an api, parseInt it first
var dateTime = new Date(parseInt(1370001284000));
dateTime.toISOString();
I am trying to get the current UTC date to store in my database. My local time is 9:11 p.m. This equates to 1:11 a.m. UTC. When I look in my database, I notice that 1:11 p.m. is getting written to. I'm confused. In order to get the UTC time in JavaScript, I'm using the following code:
var currentDate = new Date();
var utcDate = Date.UTC(currentDate.getFullYear(), currentDate.getMonth(), currentDate.getDate(), currentDate.getHours(), currentDate.getMinutes(), currentDate.getSeconds(), currentDate.getMilliseconds());
var result = new Date(utcDate);
What am I doing wrong?
A lttle searching turned out you can do this:
var now = new Date(),
utcDate = new Date(
now.getUTCFullYear(),
now.getUTCMonth(),
now.getUTCDate(),
now.getUTCHours(),
now.getUTCMinutes(),
now.getUTCSeconds()
);
Even shorter:
var utcDate = new Date(new Date().toUTCString().substr(0, 25));
How do you convert a JavaScript date to UTC?
It is a commonly used way, instead of creating a ISO8601 string, to get date and time of UTC out. Because if you use a string, then you'll not be able to use every single native methods of Date(), and some people might use regex for that, which is slower than native ways.
But if you are storing it in some kind of database like localstorage, a ISO8601 string is recommended because it can also save timezone offsets, but in your case every date is turned into UTC, so timezone really does not matter.
If you want the UTC time of a local date object, use the UTC methods to get it. All javascript date objects are local dates.
var date = new Date(); // date object in local timezone
If you want the UTC time, you can try the implementation dependent toUTCString method:
var UTCstring = date.toUTCString();
but I wouldn't trust that. If you want an ISO8601 string (which most databases want) in UTC time then:
var isoDate = date.getUTCFullYear() + '-' +
addZ((date.getUTCMonth()) + 1) + '-' +
addZ(date.getUTCDate()) + 'T' +
addZ(date.getUTCHours()) + ':' +
addZ(date.getUTCMinutes()) + ':' +
addZ(date.getUTCSeconds()) + 'Z';
where the addZ function is:
function addZ(n) {
return (n<10? '0' : '') + n;
}
Modify to suit.
Edit
To adjust a local date object to display the same time as UTC, just add the timezone offset:
function adjustToUTC(d) {
d.setMinutes(d.getMinutes() + d.getTimezoneOffset());
return d;
}
alert(adjustToUTC(new Date())); // shows UTC time but will display local offset
Take care with the above. If you are say UTC+5hrs, then it will return a date object 5 hours earlier but still show "UTC+5"
A function to convert a UTC ISO8601 string to a local date object:
function fromUTCISOString(s) {
var b = s.split(/[-T:\.Z]/i);
var n= new Date(Date.UTC(b[0],b[1]-1,b[2],b[3],b[4],b[5]));
return n;
}
alert(fromUTCISOString('2012-05-21T14:32:12Z')); // local time displayed
var now = new Date();
var utc = new Date(now.getTime() + now.getTimezoneOffset() * 60000);