September 15, 2016 @ 12:00 am - September 16, 2016 @ 12:00 am Corporations: File calendar year Form 1120 or 1120S if you timely requested a 6-month extension.
September 15, 2016 @ 12:00 am - September 16, 2016 @ 12:00 am Corporations: Deposit the third installment of your 2016 estimated tax.
September 15, 2016 @ 12:00 am - September 16, 2016 @ 12:00 am Pay the third installment of your 2016 estimated tax – Use Form 1040-ES.
