October 16, 2017 @ 12:00 am - October 17, 2017 @ 12:00 am Deposit payroll tax for Sep if the monthly deposit rule applies.
October 16, 2017 @ 12:00 am - October 17, 2017 @ 12:00 am Individuals: File Form 1040, 1040A, or 1040EZ if you timely requested a 6-month extension.
October 16, 2017 @ 12:00 am - October 17, 2017 @ 12:00 am C corporations: File calendar year Form 1120 if you timely requested a 6-month extension (see instructions).