I am using moment.js to work with dates and times in node.js. So far I've been able to do everything I need with it, but I am having problems formatting a time.
Here's the scenario:
User enters data (an integer), which is logged in a database, along with date (in the format YYYY-MM-DD) and time (in the format HH:MM:SS).
Next time the user goes to enter data, the previous value is read in and compared (higher, lower or equal to) the new value. However I also want to display a message such as "The last time you submitted your data was at TIME on DATE". In this case, I'd like time to be displayed in a different format (e.g. "h:mm a" i.e. "12:34 pm").
Can I use moment to format an existing date, or can moment only return current date/time? In my code I have the following function:
function userFormattedTime(time)
{
let uTime = moment(time).format('h:mm a');
return uTime
}
However when I call this function and pass it the time (taken from the database), I get "Invalid Time". What am I doing wrong?
You would parse the string from a string back to a moment object, then you can use moment to reformat the date into any other format.
I guess what you are doing wrong is not telling moment what you're sending it back, i.e. it doesn't understand the formatted string you're supplying.
Notice the format values HH:mm:ss which vary in case. The case is important and should be set to match your requirements. https://momentjs.com/docs/#/parsing/
// Original date time string
var rawDateTime = "02-02-2018 10:20:30";
// convert string to a moment object
var originalDate = moment(rawDateTime, "MM-DD-YYYY HH:mm:ss");
// Format a new string from the moment object
var newFormattedString = originalDate.format('h:mm a');
In order to calculate the difference of moment objects you can use the diff function. https://momentjs.com/docs/#/displaying/difference/
// Two different dates
var dateOne = moment("02-02-2018 10:20:30", "MM-DD-YYYY HH:mm:ss");
var dateTwo = moment("04-04-2018 10:20:30", "MM-DD-YYYY HH:mm:ss");
// Get the difference of the two dates
var diff = dateOne.diff(dateTwo);
Related
I am getting a date in DD-MMM-YY format, and am using dayjs to convert it to standard date format in nodejs.
However, the returned date is 1 day earlier than the input date.
I was told this is probably due to some difference in the server local time.
I can easily just add a day to the date, but as this will be a global function that works in multiple time zones, I just want to get the date "as is" without any automatic adjustments.
This is my function:
const convertDate = (date,format,zone) => {
dayjs.tz.setDefault(zone);
console.log(date);
console.log(dayjs(date));
console.log(dayjs.utc(date).$d);
console.log(dayjs.tz(date,format,zone).$d);
var newDate = dayjs.tz(date,zone);
//newDate.setDate(newDate.getDate());
return newDate;
}
No matter which methods I use or which zone I set, the date comes out as one day earlier than the input date.
For example, for a date of 01-APR-03 I get:
2003-03-31T21:00:00.000Z
I want the time to just be 2003-04-01T00:00:00.000Z.
Following comments, I have tried the following approach, but the result is the same:
const fixMonthName = (s) => s.replace(/[A-Z]{2}-/, (m) => m.toLowerCase());
const d = dayjs.utc(fixMonthName("22-FEB-02"), "DD-MMM-YY");
console.log(d);
const s = d.toISOString();
console.log(s); //{result:
M {
'$L': 'en',
'$u': true,
'$d': 2002-02-21T22:00:00.000Z,
'$x': {},
'$y': 2002,
'$M': 1,
'$D': 21,
'$W': 4,
'$H': 22,
'$m': 0,
'$s': 0,
'$ms': 0
}}
2002-02-21T22:00:00.000Z
Let's recap the problem:
You have a date-only string value of 01-APR-03 (equivalent to 2003-04-01).
You're then parsing it as timestamp, treating it as if it were 2003-04-01T00:00:00.000 (local time). This is the cause of the logical error.
Then you're looking at a UTC representation (2003-03-31T21:00:00.000Z in your example), and wondering why it's been shifted. (Z means UTC)
Fundamentally, a date and a timestamp are two different concepts. If you conflate them, you will have complications in your code such as the one you described.
A date can be thought of as a half-open range of timestamps (from the start of one day, to just before the start of the next). In other words, logically the following is true:
'2003-04-01' == ['2003-04-01T00:00:00.000', '2003-04-02T00:00:00.000')
If you parse a date-only value to an object that represents a timestamp, you are choosing to assign a point-in-time within that range. Thus, if you pick the very start of the range, you can easily shift into a different day when viewing that from another time zone.
Note that the JavaScript Date object is misnamed. It isn't a date, it's a timestamp.
A day.js object also represents a timestamp, as do most other libraries including Moment, Luxon, date-fns, and many others.
There are a few different solutions to this problem:
You can pick a time in the middle of the range which is less likely to be shifted to a different date when viewed from another time zone. For example, 12:00:00 noon. (Though this isn't perfect, as there are some time zones that go up to UTC+14.)
You can avoid treating a date as a timestamp, by keeping it in an object or string that represents it as a whole date.
Unfortunately, this isn't a concept that has caught on well in JavaScript yet. The language and most libraries do not handle it this way. (One notable exception is js-joda, which has a LocalDate data type.) However, this will eventually be coming to the JavaScript language itself via the Temporal proposal, which adds Temporal.PlainDate.
You can ignore the time portion of a timestamp and only look at the date part, but this only works if you lock all your operations to UTC rather than local time. In other words, treat '2003-04-01' as if it were '2003-04-01T00:00:00.000Z' and never convert it to local time or another time zone.
If you were using just the JavaScript Date object, then you would do:
const d = new Date('2003-04-01T00:00:00.000Z'); // the Z parses as UTC
const s = d.toISOString(); // this always emits UTC
But since you have a custom date format to parse and want to use day.js, you can do something like the following:
Define a function to work around day.js's parsing case sensitivity issue. (You need Apr, not APR.)
const fixMonthName = (s) => s.replace(/[A-Z]{2}-/, (m) => m.toLowerCase());
Parse the input string using day.js's UTC mode
const d = dayjs.utc(fixMonthName('01-APR-03'), 'DD-MMM-YY');
Get the output as a string however you would like, using any of day.js's display functions:
const s = d.toISOString(); // "2003-04-01T00:00:00.000Z"
// or
const s = d.format('YYYY-MM-DD'); // "2003-04-01"
Note that if you need a JavaScript Date object, do not use $d but instead call .toDate(). From there, make sure you are only using the UTC representation of the Date object. Keep in mind that while some environments will emit UTC when logging a Date object to the console (as if you called .toISOString(), other environments will emit the local time equivalent (as if you called .toString().
I am connected mssql database and get some informations includes Date_Time.
Time is coming like 2021-01-30T15:08:25.357Z. I want to convert it to dd-mm-yy hh:mm:ss format.
So, it should be 30-01-2021 15:08:25.
I used this method but it is not exactly that I want.
var d1 = new Date(datey).toLocaleDateString("tr")
var newTime=d1+" "+
new Date(datey).getUTCHours()+":"+
new Date(datey).getUTCMinutes()+":"+
new Date(datey).getUTCSeconds()
// it returns 30/01/2021 15:8:25
Maybe, In there, I want to see time fomat with 0 such as 15:08. When hour 2 a.m it just 2:0 but I want to see it 02:00.
How should I do , is there any idea?
I would suggest using a date/time library such as moment.js, this will make date manipulation much easier, parsing and formatting your date is then very simple:
const input= "2021-01-30T15:08:25.357Z";
console.log("Input date:", input);
// To convert the date to local before displaying, we can use moment().format()
const formattedDateLocal = moment(input).format("DD-MM-YY HH:mm:ss");
console.log("Formatted date (Local Time):", formattedDateLocal );
// To display the UTC date, we can use moment.utc().format()
const formattedDateUTC = moment.utc(input).format("DD-MM-YY HH:mm:ss");
console.log("Formatted date (UTC):", formattedDateUTC );
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>
I am working on importing data in an Excel file and it has date column.
In my app, that date column value comes as a serial number like 43101.622083333335 which stands for 01/01/2018.
When converting this serial number from Excel back to the normal date it stands for, it gives wrong year.
For example, it gives 01-Jan-1970 instead of 01-Jan-2018
``
var moment = require('moment');
var excelDate = 43101.622083333335;
var date = moment(new Date(excelDate));
var dateWithNewFormat = date.format('DD-MMM-YYYY');
console.log(dateWithNewFormat);
``
Output: 01-Jan-1970 instead of 01-Jan-2018
Any help ?
Thanks in advance.
I don't think this is an issue with the moment library. It seems that you aren't calling Date with a valid constructor argument with new Date(excelDate) (see official documentation for Date here).
The Date class doesn't understand the concept of 'Excel time' but it does understand the concept of a unix timestamp. If you refer to this post, you can see how to convert from Excel time to a unix timestamp, depending on which version of Excel you are using.
Then, I would change your code to:
var moment = require('moment');
var excelDate = 43101.622083333335;
var unixTimestamp = (excelDate-25569)*86400 //as per the post above, convert Excel date to unix timestamp, assuming Mac/Windows Excel 2011 onwards
var date = moment(new Date(unixTimestamp)); //Pass in unix timestamp instead of Excel date
var dateWithNewFormat = date.format('DD-MMM-YYYY');
console.log(dateWithNewFormat);
There is one time input i.e. start_time
I am trying to get timestamp in milliseconds for these inputs
let start_time = "17:05:00";
var start_date_moment = moment(start_time, "HH:mm:ss");
console.log(start_timestamp);
output is -> moment("2019-04-24T17:05:00.000")
This output remains same on server and local
But when I am trying to get unix timestamp in milliseconds in the same way
var start_timestamp = moment(start_time, "HH:mm:ss").valueOf();
On server at different timezone
console.log(start_timestamp);//1556125500000
console.log(moment(start_timestamp/1000).format('YYYY-MM-DD HH:mm:ss'); //2019-04-24 17:05:00
On local
console.log(start_timestamp);//1556105700000
console.log(moment(start_timestamp/1000).format('YYYY-MM-DD HH:mm:ss'); //2019-04-24 22:35:00
This start_timestamp value is different on local and server. But timestamp shouldn't change with timezone, it should remains same for all timezones. Please help me with this.
How to get the correct and same value at both places. I got this link some what related to this https://github.com/moment/moment/issues/2035
There is no issue with dates any particular format, issue is only with timestamp.
You need to take the offset into consideration when using moment (using timezones moment.js). Since no offset was passed in the input, the moment will be based on the time zone of the computer the code is running on, hence the different values..
Example:
var a = moment.tz("2013-11-18 11:55", "Asia/Taipei");
var b = moment.tz("2013-11-18 11:55", "America/Toronto");
a.format(); // 2013-11-18T11:55:00+08:00
b.format(); // 2013-11-18T11:55:00-05:00
a.utc().format(); // 2013-11-18T03:55Z
b.utc().format(); // 2013-11-18T16:55Z
If you change the time zone of a moment object using moment-timezone only affects the value of the local time. It does not change the moment in time being represented, and therefore does not change the underlying timestamp.
A Unix Timestamp is always based on UTC - you can see it as the same timestamp at any given location in the world.
Official Moment Docs on timezones
Edit:
If you use utcOffset you should pass an integer:
Example:
moment.utc("2015-10-01 01:24:21").utcOffset("-240").format('YYYYMMDD HHmmss ZZ')
// "20151001 012421 +0000"
moment.utc("2015-10-01 01:24:21").utcOffset(-240).format('YYYYMMDD HHmmss ZZ')
// "20150930 212421 -0400"
MomentJS allows offset-arguments to be passed as string, but it expects the string to be in one of the ISO8601 formats: [+/-]HH:mm or [+/-]HHmm.
To avoid this all together you could, if known, pass the location as an argument like
moment.tz(start_time, "HH:mm:ss", "Asia/Kolkata").valueOf();
as mentioned in the first example above..
When I set a value of Date/Time field in XPages It's value is like below.
I would like to set value without TimeZone (in this samples without ZE3).
Field Name: dtField1
Data Type: Time/Date
17.11.2016 13:13:31 ZE3
I tried #Today() and these 2 lines code below but I could not be succeded. is there any way to do it?
var now:NotesDateTime = session.createDateTime(#Now());
document1.replaceItemValue("dtField1", now);
Regard
C.A.
Time zone is always part of NotesDateTime field if field contains date and time no matter how you created it.
If the field contains date only or time only then time zone is omitted.
Set date only with
var now:NotesDateTime = session.createDateTime(#Now());
now.setAnyTime();
document1.getDocument().replaceItemValue("dtField1", now);
and time only with
var now:NotesDateTime = session.createDateTime(#Now());
now.setAnyDate();
document1.getDocument().replaceItemValue("dtField1", now);