Partnership returns (Form 1065) are due on March 15th, 2017 while in previous years they were due on April 15th.
C-Corporation returns (Form 1120) are due on April 18th 2017 while in previous years they were due on March 15th.
S-Corporation returns (Form 1120S) are still due on March 15th.
The Estate and Trust return (form 1041) due date remain unchanged although this year the date is April 18th, 2017.
Form 1040, 1040a and 1040ez the dates have not changed although the due date is April 18th,2017 because April 15th falls on a Saturday and the Washington DC holiday Emancipation Day is on Monday.