如何将 Firestore 日期/时间戳转换为 JS Date()？

Question

I am trying to convert the below date to a javascript Date() object. When I get it back from the server, it is a Timestamp object,

Screenshot from Firebase Firestore console:

When I try the following on a list of objects returned from firestore:

  list.forEach(a => {
    var d = a.record.dateCreated;
    console.log(d, new Date(d), Date(d))
  })

I get this output:

Clearly the Timestamps are all different, and are not all the same date of Sept 09, 2018 (which happens to be today). I'm also not sure why new Date(Timestamp) results in an invalid date . I'm a bit of a JS newbie, am I doing something wrong with the dates or timestamps?

Answer 1

The constructor for a JavaScript Date doesn't know anything about Firestore Timestamp objects - it doesn't know what to do with them.

If you want to convert a Timestamp to a Date, use the toDate() method on the Timestamp.

Answer 2

You can use toDate() function along with toDateString() to display the date part alone.

const date = dateCreated.toDate().toDateString()
//Example: Friday Nov 27 2017

Suppose you want only the time part then use the toLocaleTimeString()

const time = dateCreated.toDate().toLocaleTimeString('en-US')
//Example: 01:10:18 AM, the locale part 'en-US' is optional

Answer 3

You can use Timestamp.fromDate and .toDate for converting back and forth.

// Date to Timestamp
const t = firebase.firestore.Timestamp.fromDate(new Date());

// Timestamp to Date
const d = t.toDate();

Answer 4

请使用toDate()方法，然后使用像这样的角管将其转换为格式 -

   {{ row.orderDate.toDate() | date: 'dd MMM hh:mm' }}

Answer 5

How to convert Unix timestamp to JavaScript Date object.

var myDate = a.record.dateCreated;
new Date(myDate._seconds * 1000); // access the '_seconds' attribute within the timestamp object

Answer 6

apart from other answers you can do it like this as well

 //date from firebase is represented as let time = { seconds: 1613748319, nanoseconds: 47688698687, } const fireBaseTime = new Date( time.seconds * 1000 + time.nanoseconds / 1000000, ); const date = fireBaseTime.toDateString(); const atTime = fireBaseTime.toLocaleTimeString(); console.log(date, atTime);

Answer 7

const timeStampDate = record.createdAt;
const dateInMillis  = timeStampDate._seconds * 1000

var date = new Date(dateInMillis).toDateString() + ' at ' + new Date(dateInMillis).toLocaleTimeString()

OutPut Example: Sat 11 Jul 2020 at 21:21:10

Answer 8

At last, I could get what I need. This returns date as 08/04/2020

new Date(firebase.firestore.Timestamp.now().seconds*1000).toLocaleDateString()

Answer 9

这可能会有所帮助：

new Date(firebaseDate._seconds * 1000).toUTCString()

Answer 10

The timestamp object you get from firestore has a toDate() method you can use.

list.forEach(a => {
  var d = a.record.dateCreated;
  console.log(d.toDate())
})

Here's a quote from firebase docs about the toDate() method

Convert a Timestamp to a JavaScript Date object. This conversion causes a loss of precision since Date objects only support millisecond precision.

Returns Date JavaScript Date object representing the same point in time as this Timestamp, with millisecond precision.

https://firebase.google.com/docs/reference/js/firebase.firestore.Timestamp#todate

Answer 11

A simple way is to convert firestore timestamp to epoch timestamp is by using toMillis() method on firestore timestamp.
For example: You have a firestore timestamp
created_on : Timestamp { _seconds: 1622885490, _nanoseconds: 374000000 }

let epochTimestamp = created_on.toMillis()
//epochTimestamp = 1621081015081
//Now this timestamp can be used as usual javascript timestamp which is easy to manipulate.
let date = new Date(epochTimestamp) //date = Sat May 15 2021 17:46:55 GMT+0530 (India Standard Time)

Answer 12

这对我有用。

new Date(firebaseDate.toDate())

Answer 13

This works for me

let val = firebase.timestamp // as received from the database, the timestamp always comes in an object similar to this - {_nanoseconds: 488484, _seconds: 1635367}
    (new Date( (val.time._seconds + val.time._nanoseconds * 10 ** -9) * 1000)).toString().substring(17, 21)

Answer 14

Lots of answer here, but as a rookie I found most of them confusing.

So for rookies like me, here is a simple explanation of how to convert a Firestore date/Timestamp to a Javascript Date() and why you need to.

Why convert?

Firestore stores Dates as a Timestamp object . This is not the same as a Javascript Date() object.

This was confusing to me because if you send a Date() object to Firestore, and then retrieve it, it will hand you back a Timestamp object. Like if you hand Firestore a dollar, it will hand you back 4 quarters. It is the same amount of money (or same date), but if you were expecting paper, and got metal, you would be confused.

How to convert

Luckily the Timestamp object has functions built into do give you a Javascript Date object: toDate

Note: Remember, toDate looks like the Javascript toLocaleDateString() or toDateString() but it is not. A JS Date() object and Firestore Timestamp object are not the same so don't make my rookie mistake of trying to use functions from one, on the other.

To convert a Firestore Timestamp into a Javascript date, just call .toDate() on the Timestamp.

//get the document from Firestore
let fireStoreTimestamp = doc.data().nameOfYourDateField;
let javascriptDate = fireStoreTimestamp.toDate();

Answer 15

I had the same problem. And i figured out like this:

const createdAt = firebase.firestore.Timestamp.fromDate(new Date());

// then using dayjs library you can display your date as you want.

const formatDate = dayjs.unix(createdAt.seconds).format('YYYY-MM-DD');

Output should look like eg 2020-08-04

Answer 16

If you want don't want to lose the milliseconds you can do the following:

var myDate = a.record.dateCreated;
new Date((myDate.seconds + myDate.nanoseconds * 10 ** -9) * 1000);

Answer 17

i work in angular.

i have an interface and a field date: Date.

the angular pipe date no work: order.date | date:'medium'

i change type of field date in interface

date: firebase.firestore.Timestamp

the angular pipe date work, but with function toDate()

order.date.toDate() | date:'medium'

Answer 18

It's very simple really. Use this simple epoch converter function which converts epoch seconds into Javascript date and time.

  function getUNIXTime(dt) {
    let unix = new Date(dt * 1000);
    return unix.toUTCString().slice(5, 16);   
}

Pass the timestamp.seconds into this function then slice it according to your needs to get a string of text with date and time.

Answer 19

You can use the dayjs library to convert firebase firestore timestamp seconds to your local time.

newDate =  dayjs.unix(date.seconds).$d;

It will take

date: { 
    seconds: 1639506600, 
    nanoseconds: 0 
}

and convert it to

Date Sat Nov 16 2019 00:00:00 GMT+0530 (India Standard Time)

Answer 20

Normally using any type (ie loginDate:any) and toDate() worked without problem in my all projects. But in my last project it didn't. I saw seconds in Timestamp object is _seconds anymore (Firebase 8.6.8). This type of change may have affected it. I don't know but i had no time so i used an alternative solution. A custom pipe. It can be used as an alternative:

import { Pipe, PipeTransform } from '@angular/core';
import { formatDate } from '@angular/common';

@Pipe({
  name: 'timestamp'
})
export class TimestampPipe implements PipeTransform {

  transform(value: any, format?: string) {

    if (!value) { return ''; }
    if (!format) { format = 'dd MMM  yy'; }

    return formatDate(value._seconds * 1000, format, 'tr');
  }
}

and

{{ item.endDate | timestamp}}

PS Type is not important with this pipe. Worked with loginDate:any or loginDate:Date well.

Answer 21

to store timestamp into firestore:

import * as firebaseAdmin from "firebase-admin";

const created = firebaseAdmin.firestore.FieldValue.serverTimestamp();

// type
created: FirebaseFirestore.Timestamp | FirebaseFirestore.FieldValue | undefined;

To read back as a js Date object

const createDate = (created as FirebaseFirestore.Timestamp).toDate();

To read back as RFC3339 string

const createDate = (created as FirebaseFirestore.Timestamp).toDate().toISOString();

Answer 22

Web Firestore Timestamp:

function dateToFirestoreTimestamp(dateString = ''){
        var timestampDate = new Date();     // this will return current date-time
        if(dateString != ''){
            // this will return timestamp according to provided date-time
            dateString = dateString.replace(' ', 'T');
            timestampDate = new Date(dateString);
        } 
        timestampDate = firebase.firestore.Timestamp.fromDate(timestampDate);
        return timestampDate;
    }

Answer 23

This is by far the most elegant, precise and easiest way to convert a firebase-timestamp to a date (no dependenceis etc. needed)

const date = new Intl.DateTimeFormat(
    'de-De', { 
           year: 'numeric', 
           month: 'numeric', 
           day: 'numeric', 
           hour: 'numeric', 
           minute: 'numeric' 
    }
).format(firebaseTimeStamp.toDate())

Here is a cheatsheet with all necesarry parameters

Answer 24

this is the different thing between firestore timestamp and Javascript Date() object . if you want to use javascript Date() object from firestore timestamp, this is what I do:

const foo = new Date(firestoreTimestamp.toDate());

then you can use the javascript Date() object, as usual. here are some references:

https://www.w3schools.com/jsref/jsref_obj_date.asp

For example, we want to retrieve the date from the Date() object with string format:

const foo = new Date(firestoreTimestamp.toDate());
foo.toLocaleDateString();

etc.

Answer 25

To help those still looking around for an answer to convert Firestore Date to JS Date to display in the web app. Here goes an example using typescript...

import {
  Timestamp,
} from "firebase/firestore";

interface IStuff {
  createdAt: Timestamp;
}

const insertStuff = async (text: string) => {
    await addDoc(collection(db, "coolstuff"), {
      text,
      createdAt: serverTimestamp(),
    });
};

<p>{item.createdAt?.toDate().toDateString()}</p>

// OR

<p>{item.createdAt?.toDate().toLocaleTimeString()}</p>

Answer 26

Extending Waleed Tariq answer, to get a more readable string:

 function formatDate(date) { const formatDate = new Date( date.seconds * 1000 + date.nanoseconds / 1000000 ); return formatDate.toLocaleTimeString('en-us', { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' }); } const timeStamp = {nanoseconds: 184000000, seconds: 1664826910}; console.log(formatDate(timeStamp))