Why do Q1 and Q2 have different day counts?

Q1 has 90 days in a common year and 91 in a leap year because February is shorter. Q2 always has 91 days because April and June have 30 days and May has 31 days.

What is the difference between a fiscal quarter and a calendar quarter?

A calendar quarter follows the standard year (Jan to Dec). A fiscal quarter follows an organization's chosen fiscal year, which may start in a different month, such as October for the US federal government.

How many weeks are in each quarter?

Each quarter covers about 13 weeks, though the exact number can vary slightly depending on the year and the start day.

Calendar Quarters Explained: Q1, Q2, Q3 and Q4 Dates

Q: Can I use calendar quarters for tax planning?

Yes. US estimated income tax payments for individuals are due in April, June, September, and January, which fall at the end of each calendar quarter.

A calendar year splits into four three-month blocks. Q1 runs January 1 to March 31. Q2 runs April 1 to June 30. Q3 runs July 1 to September 30. Q4 runs October 1 to December 31. Pin down these date ranges and you can plan projects, set goals, and track deadlines without losing a week to guesswork. The guide below gives you each block's exact dates and day counts, explains the difference between calendar and fiscal blocks, and shows how to run a quarterly plan from monthly printouts.

What Are Calendar Quarters?

A quarter is a three-month block of the calendar year. Four of them make a year, and each holds about 13 weeks. The standard calendar quarters follow the Gregorian calendar and start on January 1. Businesses use them for reporting, planning, and goal setting. The months stay fixed but the day count shifts slightly, because months have different lengths and February gets an extra day in a leap year.

Q1 January 1 to March 31

Q1 is the opening block of the year. It begins on January 1 and ends on March 31. In a common year Q1 contains 90 days. In a leap year February has a longer February, so Q1 stretches to 91 days. If you are asking what months are Q1, the answer is always January, February, and March.

Q2 April 1 to June 30

Q2 starts on April 1 and ends on June 30. It holds 91 days every year, leap or not. April has 30 days, May has 31, June has 30. Q2 covers April, May, and June. Schedule mid-year reviews here; the fixed length makes comparisons clean.

Q3 July 1 to September 30

Q3 runs from July 1 to September 30. It contains 92 days every year. The months are July, August, and September. July and August each have 31 days, September has 30. Summer holidays and back-to-school planning collide in this block, so front-load the heavy work into July.

Q4 October 1 to December 31

Q4 begins on October 1 and ends on December 31. It also has 92 days. The months are October, November, and December. October and December each have 31 days, November has 30. Q4 dates drive year-end financial closing and holiday-season planning. For many organizations Q4 also marks the start of a new fiscal year.

Calendar Quarters vs Fiscal Quarters

Calendar quarters follow the standard January-to-December year. Fiscal quarters vs calendar quarters differ because fiscal quarters follow an organization's chosen fiscal year. The US federal fiscal year starts on October 1, so its fiscal Q1 is October to December. A company might start its fiscal year in July, making its Q1 July to September. Check which system your organization uses before you set a deadline.

How to Plan by Quarter Using Monthly Printouts

Identify Your Quarters

Write down the start and end dates for each block: Q1 (Jan 1 to Mar 31), Q2 (Apr 1 to Jun 30), Q3 (Jul 1 to Sep 30), Q4 (Oct 1 to Dec 31). A quarterly planning calendar breaks the year into chunks you can actually manage.

Set Quarterly Goals

For each block, list three to five main goals. In Q1 you might focus on tax preparation. US estimated income tax payments for individuals are due in April, June, September, and January, which aligns with the end of each quarter.

Use Monthly Printouts

Print a separate monthly calendar for each month in the block. For Q1 you would print January, February, and March. Mark the block's start and end dates on each printout.

Break Goals into Monthly Tasks

Divide your quarterly goals into smaller tasks for each month. Use the printout to assign due dates.

Q1 tasks: January set tax documents, February review, March finalize.
Q2 tasks: April make first estimated payment, May review progress, June prepare for summer.
Q3 tasks: July plan fall projects, August execute, September make second estimated payment.
Q4 tasks: October start year-end review, November wrap up, December make final estimated payment.

Review and Adjust

At the end of each block, review what you accomplished. Move unfinished tasks to the next block. Monthly printouts from septembercalendar.info keep your quarterly plan visible and easy to update.