Regular Expression For MM/DD/YYYY In Javascript

I've just written this regular expression in javaScript however it doesn't seem to work, here's my function: function isGoodDate(dt){ var reGoodDate = new RegExp('/^((0?[1-9]|1

Solution 1:

Attention, before you copy+paste: The question contains some syntactic errors in its regex. This answer is correcting the syntax. It is not claiming to be the best regex for date/time parsing.

Try this:

function isGoodDate(dt){
    var reGoodDate = /^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$/;
    return reGoodDate.test(dt);
}

You either declare a regular expression with:

new RegExp("^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$")

Or:

/^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$/

Notice the /

Solution 2:

Maybe because you are declaring the isGoodDate() function, and then you are calling the isCorrectDate() function?

Try:

function isGoodDate(dt){
    var reGoodDate = /^(?:(0[1-9]|1[012])[\/.](0[1-9]|[12][0-9]|3[01])[\/.](19|20)[0-9]{2})$/;
    return reGoodDate.test(dt);
}

Works like a charm, test it here.

Notice, this regex will validate dates from 01/01/1900 through 31/12/2099. If you want to change the year boundaries, change these numbers (19|20) on the last regex block. E.g. If you want the year ranges to be from 01/01/1800 through 31/12/2099, just change it to (18|20).

Solution 3:

I agree with @KooiInc, but it is not enough to test for NaN

function isGoodDate(dt){
    var dts  = dt.split('/').reverse()
       ,dateTest = new Date(dts.join('/'));
    return !isNaN(dateTest) && 
       dateTest.getFullYear()===parseInt(dts[0],10) &&
       dateTest.getMonth()===(parseInt(dts[1],10)-1) &&
       dateTest.getDate()===parseInt(dts[2],10) 
}

which will handle 29/2/2001 and 31/4/2011

---

For this script to handle US dates do

function isGoodDate(dt){
    var dts  = dt.split('/')
       ,dateTest = new Date(dt);
    return !isNaN(dateTest) && 
       dateTest.getFullYear()===parseInt(dts[2],10) &&
       dateTest.getMonth()===(parseInt(dts[0],10)-1) &&
       dateTest.getDate()===parseInt(dts[1],10) 
}

Solution 4:

Add this in your code, it working perfectly fine it here. click here http://jsfiddle.net/Shef/5Sfq6/

function isGoodDate(dt){
var reGoodDate = /^(?:(0[1-9]|1[012])[\/.](0[1-9]|[12][0-9]|3[01])[\/.](19|20)[0-9]{2})$/;
return reGoodDate.test(dt);

}

Solution 5:

I don't think you need a regular expression for this. Try this:

function isGoodDate(dt){
    var dts  = dt.split('/').reverse()
       ,dateTest = new Date(dts.join('/'));
    return isNaN(dateTest) ? false : true;
}

//explained
    var dts  = dt.split('/').reverse()
//      ^ split input and reverse the result
//        ('01/11/2010' becomes [2010,11,01]
//        this way you can make a 'universal' 
//        datestring out of it
       ,dateTest = new Date(dts.join('/'));
//     ^ try converting to a date from the 
//       array just produced, joined by '/'
    return isNaN(dateTest) ? false : true;
//         ^ if the date is invalid, it returns NaN
//           so, if that's the case, return false