Deposit payroll tax for Sep if the monthly deposit rule applies. Calendar Add to Calendar Add to Timely Calendar Add to Google Add to Outlook Add to Apple Calendar Add to other calendar Export to XML When: October 15, 2018 all-day 2018-10-15T00:00:00-07:00 2018-10-16T00:00:00-07:00 ← Electing Large Partnerships: File Form 1065-B calendar year return. Furnish Sch. K-1 to each partner. For automatic 6-month extension File Form 7004.Deposit payroll tax for payments on Jan 6-9 if the semiweekly deposit rule applies. →