The extension deadline depends on whether your business operates on a calendar year or fiscal year. The extension is due by the (original) due date of the return itself.
A partnership return/ extension must (generally) be filed by 3/15.
An "S" corporation's 1120-S return/ extension is due on the 15th day of the 3rd month following the close of the corporation's tax year.
A "C" corporation's 1120 return due on the 15th day of the 4th month following the close of the corporation's tax year. (This is a change from prior years, as it used to be 15th day of the 3rd month)
If the corporation is a calendar year taxpayer, the due date is April 18, 2017 (due to Holiday this year)
I tested a calendar year business in Turbo Tax Business (1065, 1120S), and it recognized the extension date as 3/15. Please verify that your business isn't showing a fiscal year ending in November. Also, verify that the program is updated.
