Data is stored and inquired through the API on the web page, and the API is using MongoDB.
The server space has been unified to UTC time so that the same results can be achieved in different time zones.
MongoDB uses the Mongoose schema as follows:
const userSchema = new Schema({
userId : {
type : String
},
score : {
type : Number
},
createdAt : {
type : Date,
default : Date.now
}
});
Because Date.now in the schema is in the createdAt field by default, it does not pass the Date value separately when querying the create or update of mongoose.
Considering the case where offset exists based on UTC time, the time is calculated using moment.js as follows:
// -540 offset value for KST 9 hours faster than UTC
const utc= moment.utc().add(offset, 'm').format('YYYY-MM-DDTHH:mm:ssZ');
let beginDate = new Date(utc);
let endDate = null;
let year = beginDate.getFullYear();
let month = beginDate.getMonth();
let date = beginDate.getDate();
// To view the full duration of the day
beginDate = new Date(new Date(year, month, date).setHours(0, 0, 0, 0));
endDate = new Date(new Date(year, month, date).setHours(23, 59, 59, 59));
// Find document
const user = await userSchema.aggregate([
{
$unwind : 'lists'
},
{
$match : {
'lists.createdAt' : {
$gte : beginDate,
$lte : endDate
}
}
},
...
]);
For example, if you make a query in Korea, the data inquiry may differ from the time after midnight and to 9 a.m. the next day.
What is wrong with the above parallax correction logic? I don't exactly understand the current problem.
Why so difficult? Simply use
{
$match : {
'lists.createdAt' : {
$gte : moment().startOf('day').toDate(),
$ltr : moment().endOf('day').toDate()
}
}
}
moment().startOf('day').toDate() returns the begin of current day in your local time zone. I live in Switzerland, thus it returns ISODate("2023-01-17T23:00:00.000Z")
But you can specify also a time zone, e.g.
moment.tz('Asia/Seoul').startOf('day').toDate();
ISODate("2023-01-17T15:00:00.000Z")
The problem is moment.utc().add(...) really modifies the time value. But that is not what you need to do, you like to change only the way how the time is displayed in your local time zone.
For comparison and calculations, the displayed value does not matter. All methods are done in UTC time only.
I am trying to find all users that have a matching birthday stored in the format "1975-01-12T00:00:00.000+00:00"
When I send a date of type String to my route and convert it to a date with new Date(req.body.DOB)
I am getting a date with an additional 4 hours: "1975-01-12T04:00:00.000Z" and a Z at the end.
I am new with dates so not too sure what is going on. How can I convert the string date into a date in the same way it is saved in my database, without the additional 4 hours and Z?
router.post("/api/date", async (req, res) => {
try {
const birthdate = new Date(req.body.DOB) // String as "01-12-1975"
const users = await User.find({
DOB: birthdate,
})
res.status(200).send(users)
} catch (err) {
res.status(400).send()
}
})
Databases typically use iso_8601 date format, which includes timezone. Javascript dates use the system timezone upon instantiation, if you use a format which omits the timezone (like the one you have). This is why there is an offset of 4 (offset from UTC timezone), presumably your server is in Russia or something.
You should convert the string to ISO format before converting to a date object. For example, if you store all birthdays as UTC time (at midnight), then you can just convert it like so:
const dateStr = "01-12-1975"
const [date, month, year] = dateStr.split('-')
const isoStr = `${year}-${month}-${date}T00:00:00.000Z`
const newDate = new Date(isoStr) // 1975-12-01T00:00:00.000Z
For defining a model in node.js I am using mongoose library and I want to store the date in that.
here is the schema:
availability: [
{
day: {
type: String,
},
startTime: {
type: Date,
},
endTime: {
type: Date,
},
},
]
I am passing the value from postman like below:
{
"parkingId":"62cfa09adb8bc68f045b4d65",
"day":"Monday",
"startTime":7,
"endTime": 22
}
But it is getting saved like this from 1970. I am aware that passing a time like this will calculate time from Unix epoch But I want to save today's date or date passed by merchant user for availability
day:Monday,
startTime: ISODate("1970-01-01T00:00:00.007+00:00"),
endTime: ISODate("1970-01-01T00:00:00.022+00:00")
And also what is 007+00:00 or 022+00:00?
Should I use moment library for that?
This is unrelated to MongoDB, this is a mongoose feature.
You define startTime and endTime as Date in your schema, but you are passing a number. let's see what the mongoose code does in this scenraio:
function castDate(value) {
...
let date;
if (value instanceof Number || typeof value === 'number') {
date = new Date(value);
}
...
};
As you can see in the case the input value is a number which is the case here, the mongoose schema casts this value to date using js new Date() function which is basically:
JavaScript Date objects represent a single moment in time in a platform-independent format. Date objects contain a Number that represents milliseconds since 1 January 1970 UTC.
This means when it casts new Date(7) the result is 1 January 1970 UTC + 7 mili seconds whichi is the 7 your seeing in the result 1970-01-01T00:00:00.007+00:00
Clearly in your case all you need to do is change the Date type to Number which is actually what you're trying to save.
I'm obtaining data.value which is a time in the format: hh:mm a - for example 12:30 am.
I also know:
the local timezone of the user (userTimeZone)
the timezone of the venue (venueTimeZone)
I need to convert the time selected by the user (data.value) to the correct date in the venueTimeZone. For example, if the user is in Americas/New York and they selected 1:30PM on the 20/05/2022, and the venue is in Americas/Los Angeles - the value I am interested in obtaining is 20/05/2022 10:30AM.
This is my attempt, however the timezone itself doesn't change - I think this is because when I create the userDateTime with moment I don't specify a time offset, but I'm not sure how to obtain the offset from userTimeZone, whilst accounting for DST.
const userTimeZone = _.get(
Intl.DateTimeFormat().resolvedOptions(),
['timeZone']
);
const venueDateStr = new Date().toLocaleString('en-US', {
timeZone: venueTimeZone,
});
const Date = new Date(restaurantDateStr);
const venueYear = venueDate.getFullYear();
const venueMonth = `0${venueDate.getMonth() + 1}`.slice(-2);
const venueDateOfMonth = `0${venueDate.getDate()}`.slice(-2);
const userDateTime = createDateAsUTC(
moment(
`${venueDateOfMonth}/${venueMonth}/${venueYear} ${data.value}`,
'DD/MM/YYYY hh:mm a'
).toDate()
).toLocaleString('en-US', { timeZone: venueTimeZone });
EDIT - I do not have the city offset, I have the timezone name, therefore I cannot use any suggested answer which relies on city offset.
Consider using Luxon - the successor to Moment. (See Moment's project status.)
// Parse your input string using the user's local time zone
// (this assumes the current local date)
const local = luxon.DateTime.fromFormat('1:30 pm', 'h:mm a');
// Convert to the desired time zone
const converted = local.setZone('America/Los_Angeles');
// Format the output as desired
const formatted = converted.toFormat('dd/MM/yyyy h:mm a').toLowerCase();
console.log(formatted);
<script src="https://cdnjs.cloudflare.com/ajax/libs/luxon/2.4.0/luxon.min.js"></script>
You could also do this without a library, however you may find that not all browsers will parse the input string, and your output format is up to the browser as well.
// Get the current local date as a string
const date = new Date().toLocaleDateString();
// Parse the date and time in the local time zone
// Warning: This is non-standard and may fail in some environments
const dt = new Date(date + ' 1:30 pm');
// Format the output, converting to the desired time zone
const result = dt.toLocaleString(undefined, { timeZone: 'America/Los_Angeles' });
console.log(result);
There are, of course, manual ways to parse and format dates (using regex, etc.) but I'll leave that up to you or another person to complete.
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);