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() or moment("asdasd","LT").isValid() equate to true which ideally shouldn't happen.

My application uses multiple languages and it is really not possible for me to come up with a RegEx pattern to validate the string. For example, if I get the time string as "午前12時12分0秒", Moment JS should be able to validate this. I checked the source and found that time checking is not that strict in the library. I might have missed something. Please help.

Answer 1

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