Question

9

Formatting Strings to Datetime using specific formats in Luxon

rated 0 times [ 12] [ 3] / answers: 1 / hits: 6308 / 4 Years ago, mon, november 2, 2020, 12:00:00

By now I used moment-js for time handling, but I want to switch to Luxon. But I have problems with the following implementation.

There is a textfield where you can enter a datetime in your locale time format, for instance HH:mm (24h format) or hh:mm (12h format). The used time format is stored in the variable timeFormat.

My solution with moment-js:

let timeFormat = 'HH:mm' // 'hh:mm a'

let textfield = document.querySelector('#input-time');

let timeString = textfield.value;

let dateTime = moment(timeString, timeFormat, true);



// Check if time is valid

if(dateTime.isValid() === false){

    return;

}

Using 12h-format:

11:00 am, 09:43 pm are valid.

11:00, 21:43 are invalid.

Using 24h-format:

11:00 am, 09:43 pm are invalid.

11:00, 21:43 are valid.

How can I aprove obtain a similar solution with Luxon? My biggest issue is to get a similar function to moment(timeString, timeFormat, true), so formatting a String into a Datetime using a specific format, for instance 12h/24-format.

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answered 4 Years ago bryantc · Accepted Answer

You can use fromFormat method

Create a DateTime from an input string and format string. Defaults to en-US if no locale has been specified, regardless of the system's locale.

Example:

const DateTime = luxon.DateTime;

const inputs = ['11:00 am', '09:43 pm', '11:00', '21:43'];

const formats = ['HH:mm', 'hh:mm a'];



const checkTime = (timeString, fmt) => 

  DateTime.fromFormat(timeString, fmt).isValid





for (i=0; i<inputs.length; i++) {

  for (j=0; j<formats.length; j++) {

    console.log(`${inputs[i]} with format '${formats[j]}' is valid? ` + checkTime(inputs[i], formats[j]) );

  }

}

<script src=https://cdn.jsdelivr.net/npm/[email protected]/build/global/luxon.js></script>

Have a look at For Moment users section of the manual for good reference to migrate from momentjs to Luxon.