If you’re on a calendar year, as most individuals and small businesses are, the fiscal quarter ends fall on March 31, June 30, September 30, and December 31. If your organization uses a different fiscal year, the end of each fiscal quarter falls on the last day of every third month of that year. So a fiscal year that starts July 1 ends its quarters on September 30, December 31, March 31, and June 30.
Calendar Year Quarter End Dates
Most small businesses, sole proprietors, and individual taxpayers run their fiscal year from January 1 through December 31.1Internal Revenue Service. Tax Years Under that model the four quarter ends never move:
- Q1 ends March 31 (covers January 1 through March 31)
- Q2 ends June 30 (covers April 1 through June 30)
- Q3 ends September 30 (covers July 1 through September 30)
- Q4 ends December 31 (covers October 1 through December 31)
These are the dates most people mean when they say “end of the quarter.”
Quarter Ends on a Non-Calendar Fiscal Year
A fiscal year can be any 12 consecutive months ending on the last day of a month other than December.1Internal Revenue Service. Tax Years Once the start date is set, the quarter ends follow mechanically by dividing the year into four three-month blocks.
A few worked examples:
- Fiscal year starting April 1: quarters end June 30, September 30, December 31, March 31.
- Fiscal year starting July 1: quarters end September 30, December 31, March 31, June 30.
- Fiscal year starting October 1: quarters end December 31, March 31, June 30, September 30.
- Fiscal year starting November 1: quarters end January 31, April 30, July 31, October 31.
Businesses often pick a start date that lines up with their natural operating cycle, closing the year during a slow period when inventory is low and staff can handle year-end accounting. A Northeast landscaping company, for example, might run November 1 through October 31 so the books close after the busy season and before winter.
Common Non-Calendar Fiscal Years
The U.S. Federal Government
The federal fiscal year runs October 1 through September 30 of the following calendar year.2Congress.gov. Basic Federal Budgeting Terminology Its quarters end December 31 (Q1), March 31 (Q2), June 30 (Q3), and September 30 (Q4). September 30 is the date agencies are racing toward when they’re trying to spend their budget before year-end.
Retail
Many large retailers close their fiscal year in late January or early February. Ending shortly after the holidays captures the entire shopping season, including returns and markdowns, within a single reporting cycle, and the year-end count happens when stores and warehouses are at their emptiest.
Colleges and Universities
Higher education typically uses a fiscal year ending June 30 or August 31, timed to the academic calendar. UC Irvine runs July 1 through June 30,3Accounting & Fiscal Services. Understanding Fiscal Years and Fiscal Periods while Northwestern uses September 1 through August 31.4Northwestern University. Fiscal Year End Both close between academic terms, when administrative activity is lower.
Not Every Business Can Choose Its Fiscal Year
Picking a non-calendar fiscal year isn’t open to every entity. The IRS assigns a “required tax year” to several common structures:
- S corporations must use a calendar year unless they can show the IRS a legitimate business purpose for a different year. Deferring income to shareholders doesn’t qualify as a business purpose.5Office of the Law Revision Counsel. 26 US Code 1378 – Taxable Year of S Corporation
- Partnerships generally must adopt the tax year of their majority-interest partners; if that doesn’t resolve, the year of their principal partners; and failing that, the year producing the least aggregate income deferral. Because most individual partners are on a calendar year, most partnerships end up there too.6eCFR. 26 CFR 1.706-1 – Taxable Years of Partner and Partnership
- Personal service corporations, such as medical practices, law firms, and accounting firms, must use a calendar year absent a business purpose for something else.7Office of the Law Revision Counsel. 26 US Code 441 – Period for Computation of Taxable Income
- Taxpayers with no books or no established accounting period default to the calendar year.7Office of the Law Revision Counsel. 26 US Code 441 – Period for Computation of Taxable Income
There is a narrow election under Section 444 that lets partnerships, S corporations, and personal service corporations choose a fiscal year differing from their required year by no more than three months, with an annual required payment attached.8Office of the Law Revision Counsel. 26 US Code 444 – Election of Taxable Year Other Than Required Taxable Year For most of these entities, though, the quarter ends are the calendar ones.
52/53-Week Fiscal Years Where the Date Shifts
Some companies, especially large retailers, don’t end their fiscal year on the last day of a month at all. They use a 52/53-week year that always ends on the same day of the week, such as the last Saturday in January or the Friday nearest January 31.9eCFR. 26 CFR 1.441-2 – Election of Taxable Year Consisting of 52-53 Weeks The year-end drifts by a few days each year, and every five or six years an extra week is added to keep things aligned.
Retailers favor this because it makes period-over-period sales comparisons more reliable. A standard 365-day year doesn’t divide evenly into weeks, so one calendar “month” might contain four Saturdays and the next five. The National Retail Federation’s 4-5-4 calendar addresses this by splitting each quarter into blocks of four weeks, five weeks, and four weeks, giving every quarter exactly 13 weeks. Under this method the quarter-end date shifts annually, and so do the filing and reporting cutoffs tied to it.
Deadlines That Depend on Quarter End
Knowing the exact quarter end matters because other deadlines count forward from it.
SEC Form 10-Q Filing
Publicly traded companies file a Form 10-Q for each of the first three fiscal quarters; no 10-Q is filed for Q4 because the annual Form 10-K covers that period.10Investor.gov. Form 10-Q The deadline depends on size classification:11U.S. Securities and Exchange Commission. Form 10-Q General Instructions
- Large accelerated filers and accelerated filers: 40 days after the fiscal quarter ends.
- All other filers: 45 days after the fiscal quarter ends.
A company that can’t make the deadline may file Form 12b-25 by 5:30 p.m. Eastern the next business day after the original due date, which adds five calendar days.
Estimated Tax Payment Periods
The IRS estimated tax periods for individuals are often called “quarterly,” but they don’t line up with calendar quarters. The four periods and their due dates are:12Internal Revenue Service. Individuals 2
- Period 1, January 1 through March 31: payment due April 15.
- Period 2, April 1 through May 31: payment due June 15.
- Period 3, June 1 through August 31: payment due September 15.
- Period 4, September 1 through December 31: payment due January 15 of the following year.
The second period covers two months, the third covers three, and the fourth covers four. Missing a due date can trigger an underpayment penalty even if the annual return produces a refund.12Internal Revenue Service. Individuals 2
Corporations on a fiscal year follow a different schedule: estimated tax installments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the corporation’s tax year.13Internal Revenue Service. Publication 509 (2026), Tax Calendars A corporation with a July 1 start owes installments on October 15, December 15, March 15, and June 15.
Loan Covenants
Lenders often tie loan covenants to quarterly financial results. A commercial loan agreement might require the borrower to maintain a debt-service coverage ratio of at least 1.25 at the end of every fiscal quarter. Dropping below the threshold at the quarterly measurement point, even temporarily, can trigger default provisions or force a renegotiation.