Taxes are due for C-Corp and S-Corps by March 15th. Congress has changed a lot of the tax laws and are to have the new forms out by March 1st. Check with your accountant for the new changes. Remember any profit your Corporation made, you may want to pay yourself the profit to create a loss for the corporation, and pay zero taxes. Yes, it is legal. You will be responsible for the additional income of taxes on your personal taxes though. Do the math and see if this the least amount of being taxed for your property investments and company.
Remember, the rich don’t necessarily become rich by sales and rental income alone. They are tax savers!