Per H.R. 3236 "Surface Transportation and Veterans Health Care Choice Improvement Act of 2015" signed into law by President Obama on July 31, 2015, due dates of FinCEN 114 (aka FBARs) and some IRS tax returns just changed. For tax years starting after December 31, 2015:

1. Partnership tax returns (Form 1065) are due March 15th with a 6 month extension available. Partnership tax returns were previously due April 15th with a 5 month extension;
2. Trust tax returns (Form 1041) are still due April 15th, now with a 5.5 month extension available; 
3. C corporation tax returns (Form 1120) are due April 15th with a 5 month extension available. C corporation tax returns were previously due March 15th with a 6 month extension. There are special rules for C corporations with fiscal years ending on June 30th; and 
4. FBARs - Report on Foreign Accounts (FinCEN Form 114) are due April 15th with a 6 month extension available under Treas. Reg. section 1.6081-5.FBARs were previously due on June 30th with an extension not available. 

There are several other changes, including a 6 year statute of limitations in many cases.