Using UTC dates between .NET and JavaScript - javascript

I'm using ASP.NET MVC, and I wish to store all my DateTime values on the server in UTC format. And I wish for all transmission of DateTime values to be in UTC format. But I want to display DateTimes in the browser in local time. I've been getting confused and having trouble making it work. Below is my process....
In my UI, the user is able to enter a date which I compose into a string and use to create a Date object. It ends up looking like this:
var dt = new Date("3/23/2012 8:00 AM");
So the user intends to create a Date for 8 AM their time. Now I wish to send this to the server in UTC format so I have this method:
Date.prototype.toUTC = function ()
{
var self = this;
return new Date(self.getUTCFullYear(), self.getUTCMonth(), self.getUTCDate(), self.getUTCHours(), self.getUTCMinutes());
};
Which I use like so:
data.startDt = dt.toUTC(); //Data is the object being set to the server
Then I make an Ajax call using jQuery to send the data object to the server. On the server when I debug, and examine the data that comes in I see StartDt (which is mapped to a .NET DateTime object) as being {3/23/2012 12:00:00 PM}.
This is the value I store in my database. I'm not totally certain it is correct though.
Both the client and server are located in the Eastern United States (UTC-05:00).
Now, when I send this date back to the client in JSON format .NET sends this:
"/Date(1332518400000)/"
In JavaScript I parse it this way:
var dt = new Date(parseInt(serverDt.substr(6))); //parseInt ingnores last /
My thinking is that dt is a UTC Date, but that I can display it in in local format by calling toShortTime() as shown below:
Date.prototype.get12Hour = function ()
{
var h = this.getHours();
if (h > 12) { h -= 12; }
if (h == 0) { h = 12; }
return h;
};
Date.prototype.getAMPM = function ()
{
return (this.getHours() < 12) ? "AM" : "PM";
};
Date.prototype.toShortTime = function ()
{
return this.get12Hour() + ":" + this.getMinutes() + " " + this.getAMPM();
};
But that doesn't give me the 8:00 AM back that I want. It gives me the 12:00 PM. Where am I going wrong?

In your code, dt is a UTC time. You need to convert that from UTC to local time.
See Javascript: Convert a UTC Date() object to the local timezone

Are you constructing the .NET DateTime object with the appropriate DateTimeKind value? You're sending a UTC-relative value to the server, which I'm guessing is storing the value as an EDT-relative time instead of a UTC-relative time, hence the incorrect value. As you stated, 1332518400000 is 12PM EDT, not UTC, which points to a transcription problem on the server:
> new Date(1332518400000)
Fri Mar 23 2012 12:00:00 GMT-0400 (Eastern Daylight Time)

This function works beautifully for me.
function ParseDateForSave(dateValue) {
// create a new date object
var newDate = new Date(parseInt(dateValue.substr(6)));
// return the UTC version of the date
return newDate.toISOString();
}

Related

Comparing time from different timezones with moment.js

I have a Node.js server that triggers function based on timezones. Specifically, I'm using moment-timezone and from a fixed date and time input I need to trigger action at that same input but in different time zones.
So if I set in my server that the action should be triggered at 1:00 pm UK time and the user is in New York, I want the action to be triggered at 1:00 pm in New York.
That's what I am doing now:
exports.time_to_trigger = function(hour, date) {
var user_timezone = "Asia/Tokyo";
// create date object from date + hour strings
var dateObj = moment(date + hour, process.env.DATE_FORMAT + " HH:mm a");
// create offset
var max_value = moment(dateObj).add(3, 'minutes');
var low_value = moment(dateObj).add(-3, 'minutes');
console.log(max_value); // -> moment("2018-01-25T13:03:00.000")
console.log(low_value); // -> moment("2018-01-25T12:57:00.000")
// get the now value of the user timezone
var user_now = moment.tz(moment(), user_timezone);
console.log(user_now); // -> moment.parseZone("2018-01-24T13:01:00.038+09:00")
console.log(user_now.isAfter(low_value)); // -> false
console.log(user_now.isBefore(max_value)); // -> true
return (
user_now.isAfter(low_value) &&
user_now.isBefore(max_value)
)
}
As you can see from the comment, this is not working as the comparison with isAfter and isBefore take into consideration the time zone that I converted on purpose not to have this problem. How can I solve this?
Your issue is that you use timezone to get user_now but not to create dateObj. So dateObj is missing the timezone offset and your 2 dates are not comparable as you would wish.
To have all your dates on the same timezone:
// create date object from date + hour strings
var dateObj = moment.tz(date + hour, process.env.DATE_FORMAT + " HH:mm a", user_timezone);

C# - TimeZone Issue in Asp.Net MVC

I am facing an issue in timezone. Right now I am saving time zone from client side and stored all DateTime in UTC. It's working properly but when I am trying to convert DateTime for UTC behind time zones like CST, EST, EDT it showing wrong data.
Issue -
Let's assume if I did any task at 10 PM EDT and it would be saved in DB as 2 AM(as per UTC) but when I am trying to fetch data for a day and passing current UTC date.
My question is If am trying to fetch data for a day like 11 midnight( from EST) to the current time, but my conversion from UTC to EST is wrong due to UTC 12midnight is yesterday's 8 PM(as EDT 4hr behind from UTC). (From Date[UTC convert to EDT] - 06/07/2017 08:00pm) and To Date - 06/07/2017 11:00 pm) Due to this conversion I am getting data from 8 pm to 11 pm only <- I am expecting from date is 06/07/2017 04:00 AM as per UTC.
Code -
Below is the code for conversion. In from date I have taken utcnow.date only and from a date
Javascript code -
function setTimezoneCookie() {
try {
var timezone_cookie = "timezoneoffset";
var timeZoneName = "timezonename"
var tz = jstz.determine();
var aa = tz.name();
// if the timezone cookie not exists create one.
if (!$.cookie(timezone_cookie)) {
// create a new cookie
$.cookie(timezone_cookie, new Date().getTimezoneOffset());
$.cookie(timeZoneName, aa);
}
else {
var storedOffset = parseInt($.cookie(timezone_cookie));
var currentOffset = new Date().getTimezoneOffset();
if (storedOffset !== currentOffset) {
$.cookie(timezone_cookie, new Date().getTimezoneOffset());
$.cookie(timeZoneName, aa);
location.reload();
}
else {
$.cookie(timeZoneName, aa);
}
}
}
c# code -
fromDate =Convert.ToDateTime(fromDate).ToClientTimeZoneinDateTime().ToString();
toDate = Convert.ToDateTime(toDate).ToClientTimeZoneinDateTime().ToString();
ObjectParameter totalRecords = new ObjectParameter("TotalRecords", typeof(int));
var DetailsList = objDetailsList.GetDetails(loginUserId,locationId, userId, taskType, pageIndex, numberOfRows, sortColumnName, sortOrderBy, textSearch, totalRecords, fromDate, toDate);
if (DetailsList.Count() > 0)
{
string output = BuildJQGridResults(DetailsList, numberOfRows, pageIndex, Convert.ToInt32(totalRecords.Value));
response.Write(output);
}
else
{
JQGridResults result = new JQGridResults();
List<JQGridRow> rows = new List<JQGridRow>();
result.rows = rows.ToArray();
result.page = 0;
result.total = 0;
result.records = 0;
response.Write(new JavaScriptSerializer().Serialize(result));
}
Below is the method of converting UTC time to client timezone
public static DateTime ToClientTimeZoneinDateTime(this DateTime dt)
{
try {
if (System.Web.HttpContext.Current.Request.Cookies["timezoneoffset"] != null || System.Web.HttpContext.Current.Request.Cookies["timezonename"] != null)
{
var timezonename = System.Web.HttpContext.Current.Request.Cookies["timezonename"].Value;
timezonename = timezonename.Replace("%2F", "/");
var timezoneLocal1 = FindTimezoneName(timezonename);
TimeZoneInfo tzi = TimeZoneInfo.FindSystemTimeZoneById(timezoneLocal1);
bool isCurrentlyDaylightSavings = tzi.IsDaylightSavingTime(dt);
if (isCurrentlyDaylightSavings == true)
dt.AddHours(1);
var timeOffSet = System.Web.HttpContext.Current.Request.Cookies["timezoneoffset"].Value;
var offset = int.Parse(timeOffSet.ToString());
dt = dt.AddMinutes(-1 * offset);
return dt;
}
return dt.ToLocalTime();
}
catch (Exception)
{
return DateTime.UtcNow;
}
}
No doubt as Timezone handled properly but facing an issue for behind timezone from UTC if end user trying to fetch data after 8 PM EDT. I have attached screenshot as well.
Below img of before conversion -
Above img of after conversion -
How do I need to handle this situation?
The main problem is that you're converting the wrong direction. You are converting from UTC to the user's time zone, but your input is in the user's time zone, so you need to convert the other direction - from the user's time zone to UTC. Then your query will show better results.
A few other things:
Don't convert time zones by trying to add/subtract minutes or hours manually. Use the conversion functions offered on TimeZoneInfo, such as ConvertTimeFromUtc, ConvertTimeToUtc, etc. There's no need to test for DST.
The try/catch shouldn't be in your code at all. Throw an exception if you can't perform the operation. Don't mask important errors by swallowing exceptions.
dt.ToLocalTime() shouldn't be in your code either. Never rely on the server's local time zone.
The offset returned by new Date().getTimezoneOffset() is the user's current offset. You cannot assume that it's the correct offset for the dates chosen. You don't that anyway, as you're already getting the time zone name. (You don't need the timezoneoffset cookie at all.)
The time zone name returned by jstz.determine() on the client-side is going to be an IANA tzdb identifier, such as America/Los_Angeles. These aren't going to work on the server-side with TimeZoneInfo.FindSystemTimeZoneById (unless you are running .NET Core on Linux or Mac). Conversion to a Windows time zone is required. I see you have a FindTimeZoneName function, which I assume is performing the conversion. You didn't show the details in your code, but I highly recommend you use my TimeZoneConverter library to implement that, as it's maintained with changes to time zones.
Reading cookies and time zone conversion are separate concerns. Don't bundle them together.
Ultimately, you should have something like this:
public static DateTime FromTimeZoneToUtc(this DateTime dt, string timeZone)
{
var windowsId = TimeZoneConverter.TZConvert.IanaToWindows(timeZone);
var tzi = TimeZoneInfo.FindSystemTimeZoneById(windowsId);
return TimeZoneInfo.ConvertTimeFromUtc(dt, tzi);
}
Or, even better, if you use Noda Time, then you don't need to convert time zones at all.
public static DateTime FromTimeZoneToUtc(this DateTime dt, string timeZone)
{
var tz = DateTimeZoneProviders.Tzdb[timeZone];
var local = LocalDateTime.FromDateTime(dt);
return local.InZoneLeniently(tz).ToDateTimeUtc();
}

Convert UTC to standard date time format using javascript

How can I convert a UTC time into proper date - time format using Javascript?
This is what I want to do
var d = new Date("2014-01-01");
var new_d = d.toUTC(); // 1388534400000
var old_d = function(new_d){
// return "2014-01-01" // how can i get this?
}
Now How, can i get orignal date - 2014-01-01 from 1388534400000?
****Also, Please note that when i do this --- new Date(1388534400000); it gives date 1 day less.
That is, instead of giving Jan 01 2014, it gives Dec 31 2013. But, I want Jan 01 2014.****
Is there any method to do the opposite of toUTC() method?
// _________ For those whose toUTC() doesnt work
"toUTC" method works in console of my chrome
See screen shot below
When you pass a string containing hyphens to the Date constructor, it will treat that as UTC. And if you don't pass a time, it will consider it to be midnight. If you are in a time zone that is behind UTC (such as in most of the Americas), you will see the wrong local time conversion.
Here's a screenshot of my chrome dev console, so you can see what I mean
If I pass slashes instead:
Consider using moment.js - which will accept a format parameter that will help you avoid this issue.
Try using the following:
new Date(new_d);
The problem lies with the way you instantiate the Date.
Javascript interpretes the hyphens as an utc date, and slashes as local dates.
Giving the results that mark Explains.
var utcDate = new Date('2014-01-01') // returns a UTC date
var localDate = new Date('2014/01/01'); // Returns local date
But to translate a date back to your starting point string, you can do the following.
function toDateString(utcMillis){
var date = new Date(utcMillis);
d = date.getDate();
m = date.getMonth() +1;
y = date.getFullYear();
return y + '-' + addLeadingZero(m, 2) + '-' + addLeadingZero(d,2);
}
function addLeadingZero(n, length){
n = n+'';
if(n.length<length)
return addLeadingZero('0'+n, length--);
else
return n;
}
If you find yourself with a UTC date, you can still do this:
function toUTCDateString(utcMillis){
var date = new Date(utcMillis);
d = date.getUTCDate();
m = date.getUTCMonth() +1;
y = date.getUTCFullYear();
return y + '-' + addLeadingZero(m, 2) + '-' + addLeadingZero(d,2);
}
To play around with it, and see it for yourself, see this Fiddle:

Convert date to UTC using moment.js

Probably and easy answer to this but I can't seem to find a way to get moment.js to return a UTC date time in milliseconds. Here is what I am doing:
var date = $("#txt-date").val(),
expires = moment.utc(date);
Any idea what I am doing wrong?
This is found in the documentation. With a library like moment, I urge you to read the entirety of the documentation. It's really important.
Assuming the input text is entered in terms of the users's local time:
var expires = moment(date).valueOf();
If the user is instructed actually enter a UTC date/time, then:
var expires = moment.utc(date).valueOf();
I use this method and it works. ValueOf does not work for me.
moment.utc(yourDate).format()
As of : moment.js version 2.24.0
let's say you have a local date input, this is the proper way to convert your dateTime or Time input to UTC :
var utcStart = new moment("09:00", "HH:mm").utc();
or in case you specify a date
var utcStart = new moment("2019-06-24T09:00", "YYYY-MM-DDTHH:mm").utc();
As you can see the result output will be returned in UTC :
//You can call the format() that will return your UTC date in a string
utcStart.format();
//Result : 2019-06-24T13:00:00
But if you do this as below, it will not convert to UTC :
var myTime = new moment.utc("09:00", "HH:mm");
You're only setting your input to utc time, it's as if your mentioning that myTime is in UTC, ....the output will be 9:00
This will be the answer:
moment.utc(moment(localdate)).format()
localdate = '2020-01-01 12:00:00'
moment(localdate)
//Moment<2020-01-01T12:00:00+08:00>
moment.utc(moment(localdate)).format()
//2020-01-01T04:00:00Z
moment.utc(date).format(...);
is the way to go, since
moment().utc(date).format(...);
does behave weird...
This worked for me. Others might find it useful.
let date = '2020-08-31T00:00:00Z'
moment.utc(moment(date).utc()).format() // returns 2020-08-30T22:00:00Z
If all else fails, just reinitialize with an inverse of your local offset.
var timestamp = new Date();
var inverseOffset = moment(timestamp).utcOffset() * -1;
timestamp = moment().utcOffset( inverseOffset );
timestamp.toISOString(); // This should give you the accurate UTC equivalent.
This moment.utc(stringDate, format).toDate() worked for me.
This moment.utc(date).toDate() not.
here, I'm passing the date object and converting it into UTC time.
$.fn.convertTimeToUTC = function (convertTime) {
if($(this).isObject(convertTime)) {
return moment.tz(convertTime.format("Y-MM-DD HH:mm:ss"), moment.tz.guess()).utc().format("Y-MM-DD HH:mm:ss");
}
};
// Returns if a value is an object
$.fn.isObject = function(value) {
return value && typeof value === 'object';
};
//you can call it as below
$(this).convertTimeToUTC(date);
Read this documentation of moment.js here.
See below example and output where I convert GMT time to local time (my zone is IST) and then I convert local time to GMT.
// convert GMT to local time
console.log('Server time:' + data[i].locationServerTime)
let serv_utc = moment.utc(data[i].locationServerTime, "YYYY-MM-DD HH:mm:ss").toDate();
console.log('serv_utc:' + serv_utc)
data[i].locationServerTime = moment(serv_utc,"YYYY-MM-DD HH:mm:ss").tz(self.zone_name).format("YYYY-MM-DD HH:mm:ss");
console.log('Converted to local time:' + data[i].locationServerTime)
// convert local time to GMT
console.log('local time:' + data[i].locationServerTime)
let serv_utc = moment(data[i].locationServerTime, "YYYY-MM-DD HH:mm:ss").toDate();
console.log('serv_utc:' + serv_utc)
data[i].locationServerTime = moment.utc(serv_utc,"YYYY-MM-DD HH:mm:ss").format("YYYY-MM-DD HH:mm:ss");
console.log('Converted to server time:' + data[i].locationServerTime)
Output is
Server time:2019-12-19 09:28:13
serv_utc:Thu Dec 19 2019 14:58:13 GMT+0530 (India Standard Time)
Converted to local time:2019-12-19 14:58:13
local time:2019-12-19 14:58:13
serv_utc:Thu Dec 19 2019 14:58:13 GMT+0530 (India Standard Time)
Converted to server time:2019-12-19 09:28:13
This worked for me:
const localtime = 1622516400000
moment(localtime).utc(true).format()
We can get 2 UTC date formats.
const date = '2021-07-20T18:30:00Z';
moment.utc(moment(date).utc()).format(); // 2021-07-19T18:30:00Z
moment.utc(moment(date).utc()).toISOString(); // 2021-07-20T18:30:00.000Z (Complete ISO-8601)
This works in my case.
Library: "moment": "^2.29.1",
moment().utc().format()
Don't you need something to compare and then retrieve the milliseconds?
For instance:
let enteredDate = $("#txt-date").val(); // get the date entered in the input
let expires = moment.utc(enteredDate); // convert it into UTC
With that you have the expiring date in UTC.
Now you can get the "right-now" date in UTC and compare:
var rightNowUTC = moment.utc(); // get this moment in UTC based on browser
let duration = moment.duration(rightNowUTC.diff(expires)); // get the diff
let remainingTimeInMls = duration.asMilliseconds();

JSON Stringify changes time of date because of UTC

My date objects in JavaScript are always represented by UTC +2 because of where I am located. Hence like this
Mon Sep 28 10:00:00 UTC+0200 2009
Problem is doing a JSON.stringify converts the above date to
2009-09-28T08:00:00Z (notice 2 hours missing i.e. 8 instead of 10)
What I need is for the date and time to be honoured but it's not, hence it should be
2009-09-28T10:00:00Z (this is how it should be)
Basically I use this:
var jsonData = JSON.stringify(jsonObject);
I tried passing a replacer parameter (second parameter on stringify) but the problem is that the value has already been processed.
I also tried using toString() and toUTCString() on the date object, but these don't give me what I want either..
Can anyone help me?
Recently I have run into the same issue. And it was resolved using the following code:
x = new Date();
let hoursDiff = x.getHours() - x.getTimezoneOffset() / 60;
let minutesDiff = (x.getHours() - x.getTimezoneOffset()) % 60;
x.setHours(hoursDiff);
x.setMinutes(minutesDiff);
JSON uses the Date.prototype.toISOString function which does not represent local time -- it represents time in unmodified UTC -- if you look at your date output you can see you're at UTC+2 hours, which is why the JSON string changes by two hours, but if this allows the same time to be represented correctly across multiple time zones.
date.toJSON() prints the UTC-Date into a String formatted (So adds the offset with it when converts it to JSON format).
date = new Date();
new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toJSON();
Just for the record, remember that the last "Z" in "2009-09-28T08:00:00Z" means that the time is indeed in UTC.
See http://en.wikipedia.org/wiki/ISO_8601 for details.
Out-of-the-box solution to force JSON.stringify ignore timezones:
Pure javascript (based on Anatoliy answer):
// Before: JSON.stringify apply timezone offset
const date = new Date();
let string = JSON.stringify(date);
console.log(string);
// After: JSON.stringify keeps date as-is!
Date.prototype.toJSON = function(){
const hoursDiff = this.getHours() - this.getTimezoneOffset() / 60;
this.setHours(hoursDiff);
return this.toISOString();
};
string = JSON.stringify(date);
console.log(string);
Using moment + moment-timezone libraries:
const date = new Date();
let string = JSON.stringify(date);
console.log(string);
Date.prototype.toJSON = function(){
return moment(this).format("YYYY-MM-DDTHH:mm:ss:ms");;
};
string = JSON.stringify(date);
console.log(string);
<html>
<header>
<script src="https://momentjs.com/downloads/moment.min.js"></script>
<script src="https://momentjs.com/downloads/moment-timezone-with-data-10-year-range.min.js"></script>
</header>
</html>
Here is another answer (and personally I think it's more appropriate)
var currentDate = new Date();
currentDate = JSON.stringify(currentDate);
// Now currentDate is in a different format... oh gosh what do we do...
currentDate = new Date(JSON.parse(currentDate));
// Now currentDate is back to its original form :)
you can use moment.js to format with local time:
Date.prototype.toISOString = function () {
return moment(this).format("YYYY-MM-DDTHH:mm:ss");
};
I'm a little late but you can always overwrite the toJson function in case of a Date using Prototype like so:
Date.prototype.toJSON = function(){
return Util.getDateTimeString(this);
};
In my case, Util.getDateTimeString(this) return a string like this: "2017-01-19T00:00:00Z"
I run into this a bit working with legacy stuff where they only work on east coast US and don't store dates in UTC, it's all EST. I have to filter on the dates based on user input in the browser so must pass the date in local time in JSON format.
Just to elaborate on this solution already posted - this is what I use:
// Could be picked by user in date picker - local JS date
date = new Date();
// Create new Date from milliseconds of user input date (date.getTime() returns milliseconds)
// Subtract milliseconds that will be offset by toJSON before calling it
new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toJSON();
So my understanding is this will go ahead and subtract time (in milliseconds (hence 60000) from the starting date based on the timezone offset (returns minutes) - in anticipation for the addition of time toJSON() is going to add.
JavaScript normally convert local timezone to UTC .
date = new Date();
date.setMinutes(date.getMinutes()-date.getTimezoneOffset())
JSON.stringify(date)
Usually you want dates to be presented to each user in his own local time-
that is why we use GMT (UTC).
Use Date.parse(jsondatestring) to get the local time string,
unless you want your local time shown to each visitor.
In that case, use Anatoly's method.
Got around this issue by using the moment.js library (the non-timezone version).
var newMinDate = moment(datePicker.selectedDates[0]);
var newMaxDate = moment(datePicker.selectedDates[1]);
// Define the data to ask the server for
var dataToGet = {"ArduinoDeviceIdentifier":"Temperatures",
"StartDate":newMinDate.format('YYYY-MM-DD HH:mm'),
"EndDate":newMaxDate.format('YYYY-MM-DD HH:mm')
};
alert(JSON.stringify(dataToGet));
I was using the flatpickr.min.js library. The time of the resulting JSON object created matches the local time provided but the date picker.
Here is something really neat and simple (atleast I believe so :)) and requires no manipulation of date to be cloned or overloading any of browser's native functions like toJSON (reference: How to JSON stringify a javascript Date and preserve timezone, courtsy Shawson)
Pass a replacer function to JSON.stringify that stringifies stuff to your heart's content!!! This way you don't have to do hour and minute diffs or any other manipulations.
I have put in console.logs to see intermediate results so it is clear what is going on and how recursion is working. That reveals something worthy of notice: value param to replacer is already converted to ISO date format :). Use this[key] to work with original data.
var replacer = function(key, value)
{
var returnVal = value;
if(this[key] instanceof Date)
{
console.log("replacer called with key - ", key, " value - ", value, this[key]);
returnVal = this[key].toString();
/* Above line does not strictly speaking clone the date as in the cloned object
* it is a string in same format as the original but not a Date object. I tried
* multiple things but was unable to cause a Date object being created in the
* clone.
* Please Heeeeelp someone here!
returnVal = new Date(JSON.parse(JSON.stringify(this[key]))); //OR
returnVal = new Date(this[key]); //OR
returnVal = this[key]; //careful, returning original obj so may have potential side effect
*/
}
console.log("returning value: ", returnVal);
/* if undefined is returned, the key is not at all added to the new object(i.e. clone),
* so return null. null !== undefined but both are falsy and can be used as such*/
return this[key] === undefined ? null : returnVal;
};
ab = {prop1: "p1", prop2: [1, "str2", {p1: "p1inner", p2: undefined, p3: null, p4date: new Date()}]};
var abstr = JSON.stringify(ab, replacer);
var abcloned = JSON.parse(abstr);
console.log("ab is: ", ab);
console.log("abcloned is: ", abcloned);
/* abcloned is:
* {
"prop1": "p1",
"prop2": [
1,
"str2",
{
"p1": "p1inner",
"p2": null,
"p3": null,
"p4date": "Tue Jun 11 2019 18:47:50 GMT+0530 (India Standard Time)"
}
]
}
Note p4date is string not Date object but format and timezone are completely preserved.
*/
I ran into the same problem.
The way I resolvet it was:
var currentTime = new Date();
Console.log(currentTime); //Return: Wed Sep 15 13:52:09 GMT-05:00 2021
Console.log(JSON.stringify(currentTime)); //Return: "2021-09-15T18:52:09.891Z"
var currentTimeFixed = new Date(currentTime.setHours(currentTime.getHours() - (currentTime.getUTCHours() - currentTime.getHours())));
Console.log(JSON.stringify(currentTimeFixed)); //Return: "2021-09-15T13:52:09.891Z"
I wrote the following code blog where it makes service calls.. it will try to serializable the json in every post submission, it will format to local date it again.
protected async post(endPoint: string, data, panelName?: string, hasSuccessMessage: boolean = false): Promise<Observable<any>> {
const options = this.InitHeader(true);
const url: string = this._baseUrl + endPoint;
Date.prototype.toJSON = function () {
return moment(this).format("YYYY-MM-DDThh:mm:00.000Z");;
};
return await this._http.post(url, data, options).pipe(map(response => {
return this.Map<any>(response, null);
}));
}
All boils down to if your server backend is timezone-agnostic or not.
If it is not, then you need to assume that timezone of server is the same as client, or transfer information about client's timezone and include that also into calculations.
a PostgreSQL backend based example:
select '2009-09-28T08:00:00Z'::timestamp -> '2009-09-28 08:00:00' (wrong for 10am)
select '2009-09-28T08:00:00Z'::timestamptz -> '2009-09-28 10:00:00+02'
select '2009-09-28T08:00:00Z'::timestamptz::timestamp -> '2009-09-28 10:00:00'
The last one is probably what you want to use in database, if you are not willing properly implement timezone logic.
Instead of toJSON, you can use format function which always gives the correct date and time + GMT
This is the most robust display option. It takes a string of tokens
and replaces them with their corresponding values.
I tried this in angular 8 :
create Model :
export class Model { YourDate: string | Date; }
in your component
model : Model;
model.YourDate = new Date();
send Date to your API for saving
When loading your data from API you will make this :
model.YourDate = new Date(model.YourDate+"Z");
you will get your date correctly with your time zone.
In this case I think you need transform the date to UNIX timestamp
timestamp = testDate.getTime();
strJson = JSON.stringify(timestamp);
After that you can re use it to create a date object and format it. Example with javascript and toLocaleDateString ( https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/Date/toLocaleDateString )
newDateObject = new Date(JSON.parse(strJson));
newDateObject = newDateObject.toLocalDateStrin([
"fr-FR",
]);
If you use stringify to use AJAX, now it's not useful. You just need to send timestamp and get it in your script:
$newDateObject = new \DateTime();
$newDateObject->setTimestamp(round($timestamp/1000));
Be aware that getTime() will return a time in milliseconds and the PHP function setTimestamp take time in seconds. It's why you need to divide by 1000 and round.
In Angular place the following in index.js script section:
setTimeout(function (){
Date.prototype.toJSON = function(){
return new Date(this).toLocaleDateString("en-US") + " "+new Date(this).toLocaleTimeString();
}},1000);

Categories