Javascript dates are a day off?

Question

I am trying to use a simple date function in my application to pass a date in the format of yyyy-mm-dd such as 2017-07-30 and have it returned in the format of 07/30/2017.

However, when I try this, I supply my date correctly but it outputs one day shorter than what I am looking for.

function format(inputDate) {
    var date = new Date(inputDate);
    if (!isNaN(date.getTime())) {
        var day = date.getDate().toString();
        var month = (date.getMonth() + 1).toString();
        // Months use 0 index.

        return (month[1] ? month : '0' + month[0]) + '/' +
           (day[1] ? day : '0' + day[0]) + '/' + 
           date.getFullYear();
    }
}

console.log(format('2017-07-30'));

Here is a fiddle: http://jsfiddle.net/49pptrj4/

Any thoughts as to why this is returning incorrectly?

Result on my end:

Javascript dates are a day off?

1 Answers