Calculate date + 30 days then first of following month

I have a calculated field in my form that adds 30 days to a date entered into DateofHire. I need the resulting date to be the first of the following month.

Ex:

Using a hire date of 7/1/17 my script results in 7/31/17, I need to calculate it to 8/1/17.

If the hire date is 7/2/17, the script results in 8/1/17, I need the field to go to 9/1/17.

I hope that makes sense. Here's my current script:

// Custom Calculate script for NewDate field

(function () {

    // Get date entered into the DOH field

    var sDate = getField("DateofHire").valueAsString;

    // Convert string to date

    var d = util.scand("mm/dd/yyyy", sDate);

   // Add days to date

    d.setDate(d.getDate() + 30);

    // Populate this field with the result

    if (sDate) {

        event.value = util.printd("mm/dd/yyyy", d);

    } else {

        event.value = "";

    }

})();