Sort Data and Time String in Javascript

Question

I Know there are lot of answers out there to sort date and time. But in every answer, they sort only date or they sort only time. I can't find the answer which sorts both date and time string.

Here's the Code I tried:

var x = [ '29/09/2020 11:55:56', '04/08/2021 11:57:06', '30/09/2019 15:19:49', '04/08/2021 13:57:06' ]
x.sort((a, b) => new Date(b).getTime() - new Date(a).getTime()).reverse();
console.log(x)

Output I got:

["04/08/2021 13:57:06", "30/09/2019 15:19:49", "04/08/2021 11:57:06", "29/09/2020 11:55:56"]

Required Output:

["04/08/2021 13:57:06","04/08/2021 11:57:06", "29/09/2020 11:55:56", "30/09/2019 15:19:49", ]

I searched whole day. Please Help me with some solutions to fix this.

I think that this is what you are looking for [How to sort an object array by date property?](https://stackoverflow.com/questions/10123953/how-to-sort-an-object-array-by-date-property) — JK97Tae, Sep 30 '21 at 10:39
Just a hint. Try this `[ new Date('29/09/2020 11:55:56'), new Date('04/08/2021 11:57:06'), new Date('30/09/2019 15:19:49'), new Date('04/08/2021 13:57:06') ]` and you get this `[Invalid Date, Thu Apr 08 2021 11:57:06 GMT+0200 (Central European Summer Time), Invalid Date, Thu Apr 08 2021 13:57:06 GMT+0200 (Central European Summer Time)]` so there's no surprise it doesn't work as you expect since there are 2 invalid dates. All you need to do is to fix the date string format. Your code should work just fine. — Molda, Sep 30 '21 at 10:41
Your problem is using the [built–in parser](https://262.ecma-international.org/#sec-date.parse) to parse an unsupported timestamp format. You can write a simple function to parse the timestamps correctly, then sort as `(a, b) => myParse(a) - myParse(b)`. — RobG, Sep 30 '21 at 11:11

score 0 · Answer 1 · answered Sep 30 '21 at 10:45

0

The problem is that Date uses a yyyy/mm/dd format instead of a dd/mm/yyyy format. So all your Date objects are Invalid Date.

P.S. If you sort but have to reverse the order afterwards, just reverse the subtractions.

answered Sep 30 '21 at 10:45

SMJS

94
10

Not all dates are invalid, only the 1st and the 3rd. Although even 2nd and 4th are not parsed as expected. – Molda Sep 30 '21 at 10:51
I think it's mostly a miracle that 2/4 even parse to begin with if the format isn't correct. – SMJS Sep 30 '21 at 10:53
Parsing any string other than those supported by ECMA-262 (essentially the formats produced by [*date.toISOString*](https://262.ecma-international.org/#sec-date.prototype.toisostring) and [*date.toString*](https://262.ecma-international.org/#sec-date.prototype.tostring)) with the built–in parser is implementation dependent and should be strongly discouraged. – RobG Sep 30 '21 at 11:17

pilchard · Answer 2 · 2021-09-30T11:40:57.023

Date and time are not separate in the context of a javascript Date object, internally they are just stored as millisecond offsets. But, you can't rely on Date parsing strings for you. Write a custom parser for you specific date-time strings and then then simply subtract dates.

There's no need for reverse() either, simply switch the subtraction to change direction.

const x = [ '29/09/2020 11:55:56', '04/08/2021 11:57:06', '30/09/2019 15:19:49', '04/08/2021 13:57:06' ];

const parse_date_string = (str) => {
  const [date, time]= str.split(' ');
  const [day, month, year] = date.split('/');
  const [hr, min, sec] = time.split(':');
   
  return [year, (month - 1), day, hr, min, sec].map(Number);
}

x.sort((a, b) => new Date(...parse_date_string(b)) - new Date(...parse_date_string(a)));


console.log(x)

Why not `let [day, month, year, hr, min, sec] = str.split(/\W/)`? Don't forget to subtract 1 from the (calendar) month. :-) — RobG, Sep 30 '21 at 11:19
Fair points, I was going for clarity in the splits for the OP's sake, but the month is def an oversight. — pilchard, Sep 30 '21 at 11:37

score 0 · Answer 3 · answered Sep 30 '21 at 10:47

if momentjs an option:

var x = [ '29/09/2020 11:55:56', '04/08/2021 11:57:06', '30/09/2019 15:19:49', '04/08/2021 13:57:06' ];
x.sort((a, b) => moment(b,"DD-MM-YYYY hh:mm:ss") - (moment(a,"DD-MM-YYYY hh:mm:ss")));
console.log(x)

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>

score 0 · Answer 4 · answered Sep 30 '21 at 10:55

I think this is a very hard task when you try to compare date and time in strings. And would take to much time when executing. Instead i would convert date and times to timestamp format then compare. To convert a date string to a timestamp format i referred to the answer on this stackoverflow question

const dates = [ '29/09/2020 11:55:56', '04/08/2021 11:57:06', '30/09/2019 15:19:49', '04/08/2021 13:57:06' ];
dates.sort((date1,date2) => {
    var dateTimeParts = date1.split(' '),
    timeParts = dateTimeParts[1].split(':'),
    dateParts = dateTimeParts[0].split('/'),
    date1;

    date1 = new Date(dateParts[2], parseInt(dateParts[1], 10) - 1, dateParts[0],         timeParts[0], timeParts[1], timeParts[2]);
    
    var dateTimeParts2 = date2.split(' '),
    timeParts2 = dateTimeParts2[1].split(':'),
    dateParts2 = dateTimeParts2[0].split('/'),
    date2;

    date2 = new Date(dateParts2[2], parseInt(dateParts2[1], 10) - 1, dateParts2[0],         timeParts2[0], timeParts2[1], timeParts[2]);
    return date1.getTime() / 1000 - date2.getTime() / 1000
});

console.log(dates);

Consider `let [D,M,Y, H, m, s] = '29/09/2020 11:55:56'.split(/\W/); let d = new Date(Y, M-1, D, H, m, s)`. :-) — RobG, Sep 30 '21 at 11:14

Sort Data and Time String in Javascript

4 Answers4