Is there a way to validate time using Moment JS?

Question

Is there a way to validate if the String passed as time is valid using Moment JS?

The operations moment(\"2014-12-13 asdasd\",\"YYYY-MM-DD LT\").isValid() o

Answer 1

const allPossibleFormats = [
  'D MMMM YYYY',
  'D MMMM YYYY HH:mm',
  'DD-MM-YY',
  'DD-MM-YYYY',
  'DD.MM.YYYY',
  'DD.MM.YYYY HH:mm',
  'DD/MM/YY',
  'DD/MM/YYYY',
  'DD/MM/YYYY HH:mm:ss',
  'HH:mm:ss',
  'M/D/YYYY',
  'D/M/YYYY',
  'MM-DD-YY',
  'MM-DD-YYYY',
  'MM-DD-YYYY HH:mm:ss',
  'MM/DD/YY',
  'MM/DD/YYYY',
  'MM/DD/YYYY HH:mm:ss',
  'MMM D YYYY',
  'MMM D YYYY LT',
  'MMMM Do YYYY',
  'MMMM Do YYYY LT',
  'YYYY-DD-MM HH:mm:ss',
  'YYYY-MM',
  'YYYY-MM-DD',
  'YYYY-MM-DD HH:mm',
  'YYYY-MM-DD HH:mm:ss',
  'YYYY-MM-DD LT',
  'YYYY-MM-DD h:mm:ss A',
  'YYYY-MM-DDTHH:mm:ssZ',
  'ffffd, MMM D YYYY LT',
  'ffffdd D MMMM YYYY HH:mm',
  'ffffdd, MMMM Do YYYY LT'
];

moment('Chicago Illinois 46702', allPossibleFormats, true).isValid(); // false
moment('18/01/1944', allPossibleFormats, true).isValid(); // true
moment('22-10-2020', allPossibleFormats, true).isValid(); // true
moment('1944-01-18 12:00:00', allPossibleFormats, true).isValid(); // true
moment('2001-01-01 00:00:00', allPossibleFormats, true).isValid(); // true
moment('2001-01', allPossibleFormats, true).isValid(); // true

<script src="https://momentjs.com/downloads/moment.js"></script>

Answer 2

As described in the documentation, as of moment 2.3.0, you can pass a third parameter true which turns on "strict parsing" mode.

moment("2014-12-13 asdasd","YYYY-MM-DD LT", true).isValid()   // false

moment("2014-12-13 12:34 PM","YYYY-MM-DD LT", true).isValid()   // true

The down side is that it must match the locale's format (i.e. the one supplied as the second argument) exactly. Since LT is equivalent to h:mm A in English, it will only accept 12-hour time without seconds. If you pass 24 hour time, or pass seconds, then it will fail.

moment("2014-12-13 12:34:00 PM","YYYY-MM-DD LT", true).isValid()   // false
moment("2014-12-13 15:00","YYYY-MM-DD LT", true).isValid()         // false

A better solution might be to pass multiple formats with strict parsing:

var formats = ["YYYY-MM-DD LT","YYYY-MM-DD h:mm:ss A","YYYY-MM-DD HH:mm:ss","YYYY-MM-DD HH:mm"];
moment("2014-12-13 12:34 PM", formats, true).isValid()     // true
moment("2014-12-13 15:00", formats, true).isValid()        // true
moment("2014-12-13 12:34:00 PM", formats, true).isValid()  // true