Edit in JSFiddle

function IsDate(event) {
    var chCode = ('charCode' in event) ? event.charCode : event.keyCode;
    if (chCode >= 48 && chCode <= 57) {
        return true;
    }
    else if (chCode == 45) {
        var s = obj.value.split('-');
        if (s.length>2) 
            {
            alert('Too many dashes. Only numbers or two dashes.');
            return false;
        }
        return true;
    }
    else {
        alert('Numbers only and dashes only');
        return false;
    }
}

function IsValidEmail(o)
{
    var d2 = o.value.split('-');
            var d;
            if (d2[1] >= 1 && d2[1] <= 12)
                d = new Date(d2[0], d2[1]-1, d2[2]);
            if (isNaN(d)) {
                
                alert('Invalid Date: ' );
            }
            else {
                var m = d.getMonth() + 1;
                var mm, dd;            
                if (d.getDate() < 10)
                    dd = '0' + d.getDate();
                else
                    dd=d.getDate()
                if (m < 10)
                    mm = '0' + m;
                else
                    mm = m;
                o.value = d.getFullYear() + "-" + mm + '-' + dd;
            }
}

<a href='http://z54.com'>Is Date format Validation</a><br>
Example: <input type='text' onkeypress='return IsDate(event)' onblur='IsValidEmail(this)' />