I'm trying to parse the value of a datetime-local input so the format is 'yyyy-mm-ddTHH:mm'. I want the assumption to be that I'm parsing in the local time zone of the user, i.e. if they enter 09:00 they mean 9am in their time zone.
Also not just the current time offset, e.g. if the user enters a date in June then they mean daylight savings time regardless of the fact it's now November and DST has ended.
I've tried using regular Date objects and moment.js but the assumption is always that the time zone is UTC.
Is there a way to do this?
// dateString is the value from datetime-local
var dateInLocal = moment(dateString, "YYYY-MM-DDThh:mm");
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I am having trouble when converting from time zone to time zone using moment.js.
This is my code:
convertSelectedTimeZoneToClients() {
let timeZoneInfo = {
usersTimeZone: this.$rootScope.mtz.tz.guess(),
utcOffset: this.formData.timeZone.offset,
selectedDateTime: this.toJSONLocal(this.formData.sessionDate) + " " + this.formData.sessionTime
};
let utcTime = this.$rootScope.mtz.utc(timeZoneInfo.selectedDateTime).utcOffset(timeZoneInfo.utcOffset).format("YYYY-MM-DD HH:mm");
let con = this.$rootScope.mtz.tz(utcTime, timeZoneInfo.usersTimeZone).format();
return con;
}
The user picks date, time and time zone from drop downs on client page.
In timeZoneInfo object I am storing usersTimeZone (I want to be able to convert timezone that user selected on page and convert it to his local time zone).
For example user picks: 11/08/2016 01:30 and UTC+2 timezone and his timezone is UTC+1, than I want to show him in label: That is 11/08/2016 00:30 since UTC+1 is -1 hour comparing to UTC+2 timezone.
I store offsets for time zones in one object and those values are hard coded (utcOffset: this.formData.timeZone.offset).
Before I convert time form time zone to time zone I do this: get time zone -> convert to UTC time -> convert to user time zone.
What is happening is that utcTime variable has correct value. But when I pass that value and users time zone to .tz() function and using format() to get some readable value I get same time as utcTime like shown in picture:
I have read moment.js docs and by them this .tz().format() should do the work, but as you can see my result is: 2016-11-08T23:30:00+01:00.
So it gets that is should be incremented by 1 hour but how to accomplish to get: 2016-11-09T00:30 instead?
I have tried .format("YYYY-MM-DD HH:mm") as well same problem. When I use .local() function that should convert from utc time to specified time zone same problem is present.
Am I getting something wrongly? I am pretty sure that when you convert from 2016-11-08T23:30 UTC to UTC+1 it should be 2016-11-09T00:30, or one hour forward. Does someone sees something strange in this code?
I'm using moment.js with timezones to create a datetime belonging to a specific timezone:
var datetime = moment.tz("2016-08-16 21:51:28","Europe/London");
Because this constructor is aware of DST (daylight saving time), moment.js will add +1 hour offset automatically. datetime.format() will show: 2016-08-16T21:51:28+01:00.
But it seems when printing the date, the offset ins't considered. E.g. datetime.format('DD.MM.YYYY - HH:mm:ss') will show: 16.08.2016 - 21:51:28 but I wan't it to show: 16.08.2016 - 22:51:28 (the time considering the DST-Offset of 1 hour). Does anyone know how to do this?
You are misinterpreting the output you're getting.
When you see +01:00 at the end of an ISO8601 timestamp, it doesn't mean that you need to add an hour. It means that timestamp given is in a local time zone that is one hour ahead of UTC at that point in time. Moment isn't adding an hour. It's simply reflecting the local time in London.
For the timestamps you provided, showing 22:51:28 would be an error. The local time in London is 21:51:28, and the equivalent UTC time is 20:51:28. You wouldn't find 22:51:28 until you went one time zone to the East, at UTC+2.
Now, if what you meant to do is convert from UTC to London time, then you need to create the input as UTC and then convert.
moment.utc("2016-08-16 21:51:28").tz("Europe/London")
Then you'd get 22:51:28 when formatting, which is the result you asked for, but this is a different point in time.
I have dates in my database set to Europe/London time. I am using Moment.js to show relative time e.g. "3 minutes ago". This works fine for me as I am in the same timezone, but for example, someone who is PST timezone would see "in 8 hours". How can I fix this?
My current code is like this:
$('time').text( moment( '2016-01-22 18:00:00' ).fromNow() );
To echo Jon's answer, moment's relative time functionality is strictly UTC based, so the behavior you describe won't actually happen, unless you are interpreting the original timestamp in local time.
It's hard to say if you're doing that or not, as you didn't give a sample value of the input string.
If your times are indeed UTC based, but that's not reflected in the input string, then use moment.utc instead of just moment.
And no, London is not the same as UTC.
I believe that the best approach is to store the date in UTC and then convert this to the local time zone for display. Note that this is not necessarily the same as London time because UTC does away with daylight savings time nonsense. You can do everything that you need with the date class provided the time stamp stored in the database does not have to deal with the vagaries of time zone and DST. The date class maintains its own epoch internally as milliseconds elapsed since midnight 1 January 1970 UTC. You can evaluate the difference between two Date objects as follows:
var agora = Date.now();
var stored = ... // the date that was stored in your database
var diff_msec = agora.getTime() - stored.getTime();
Knowing that the difference and that its units are milliseconds, you can convert the difference to whatever units are best for presentation.
I am working on a conversion of an UTC date.
The date format received from the server inside the JSON file has the following format:
"OpenDate":"2015-10-26T08:00:00Z"
I translate the date using the following function:
var myDate = myJson.OpenDate.toLocaleString();
The problem occurs after 25th of October, when the legal time is changed. After 25th of October my dates are 1 hour earlier, which they shouldn't. So how can I keep into consideration the change in time? If the appointment says 8 a.m. UTC it should be always 9 a.m. for our timezone, even when the legal time is changed.
I have a problem converting a timestamp in javascript.
I have this timestamp:
2011-10-26T12:00:00-04:00
I have been trying to format it to be readable. So far, it converts this using the local time of my system instead of the GMT offset in the timestamp. I know the timezone that this was created in is EST. I'm in PST, so the times are being offset by 3 hours.
Instead of this showing as:
Wednesday October 26, 2011 12:00 pm
It shows as:
Wednesday October 26, 2011 9:00 am
I have tried a few different solutions, but the latest one is found here: http://blog.stevenlevithan.com/archives/date-time-format
I am less concerned with the formatting part as I am with figuring out how to handle the GMT offsets. Would appreciate any help and insight anyone can provide.
Date objects are created in the local zone. If the date string was created in a different time zone, then you need to adjust the date object to allow for the difference.
The abbreviations PST and EST are ambiguous on the web, there is no standard for time zone abbreviations and some represent two or zones. You should express your zone only in terms of +/- UTC or GMT (which are the same thing, more or less).
You can get the local time zone offset using Date.prototype.getTimezoneOffset, which returns the offset in minutes that must be added to a local time to get UTC. Calculate the offset for where the time string was created and apply it to the created date object (simply add or subtract the difference in minutes as appropriate).
If your time zone is -3hrs, getTimezoneOffset will return +180 for a date object created in that zone. If the string is from a zone -4hrs, its offset is +240. So you can do:
var localDate = new Date('2011-10-26T12:00:00') // date from string;
var originOffset = 240;
var localOffset = localDate.getTimezoneOffset();
localDate.setMinutes( localDate.getMinutes() + originOffset - localOffset );
Adding the origin offset sets it to UTC, subracting the local offset sets it to local time.
It would be much easier if the time string that was sent by the server was in UTC, that way you just apply the local offset.
Edit
IE will not parse a time string with an offset, and Chrome thinks that the above time string is UTC and adjusts for local offset. So don't let Date parse the string, do it manually.
It doesn't matter what time zone you are- the time stamp will result in a different local time for every different time-zone, but they all will be correct, and anyone checking the UTC time of the date will get the same time-stamp:
new Date('2011-10-26T12:00:00-04:00').toUTCString()
returns
Wed, 26 Oct 2011 16:00:00 GMT
and getTime() anywhere returns the same milliseconds universal timestamp:1319644800000