MAY 10 Employers: Deferred due date from 941 if timely deposits were made. 15 Exempt Organizations: File 2012 Form 990, 990-EZ, or 990-N, if the organization reports on a calendar-year basis. 15 Partnerships and S Corporations: If an election to use a tax year other than a required tax year was made, file Form 8752 to report the required payment. JUNE 17 Individuals: Second installment of 2013 estimated tax due; file Form 1040-ES. 17 Corporations: Deposit second installment of estimated income tax for 2013, if the organization reports on a calendar-year basis. JULY 31 Employee Benefit Plan Sponsors: File 2012 Form 5500 or Form 5500-EZ. If your plan is not a calendar-year plan, file the form by the end of the seventh month after the plan year ends. 31 Employers: File Form 941, Employer's Quarterly Federal Tax Return; quarterly deposit due.