Quarter Calendar Generator

The quarter calendar shows civil Q1–Q4 as month-grid clusters for a year, plus each quarter’s start and end dates. Q1 is January–March, Q2 April–June, Q3 July–September, Q4 October–December. That is the civil quarter system, not a fiscal quarter from an October start, and not the quarter calculator that classifies a single date into Q1–Q4 without drawing months.

Civil quarters, fixed months

Each quarter is three named civil months. Day counts differ: Q1 includes February’s 28 or 29 days, so Q1 length is 90 or 91 days. Q2 is 91 days. Q3 is 92. Q4 is 92. Those lengths matter for “even quarters” rhetoric that is not actually even in day count.

The quarter calculator answers which civil quarter contains a date. This page answers what those four quarters look like as calendars. One is a lookup; the other is a year of clustered grids. Keep them unmerged in documentation.

Not fiscal and not retail

Federal fiscal Q1 under October start is October–December of the prior civil year relative to the FY number. That cluster is civil Q4 of the earlier year. If a report says FQ1, use fiscal calendar or the fiscal year calculator, not this civil quarter page.

Retail 4-5-4 quarters are 13-week buckets from a February-adjacent Sunday, not January–March. A “Q1” in a 4-5-4 deck is not this Q1. Use the 4-5-4 generator for that language.

How to use the clusters

Enter a year and calculate. Read four groups of three month grids and the inclusive start/end dates (January 1–March 31, and so on). Leap years extend Q1 through February 29. 2026 uses that year’s leap status.

Holiday marks are not the purpose here. Overlay 2026 holidays if a quarterly business review needs federal closures inside Q4, especially Thanksgiving week.

Worked examples

A sales ops team prints civil Q3 month grids for a summer campaign that is billed on calendar quarters, not fiscal. They had been using July–September fiscal labels from an October-start FY, which is actually fiscal Q4. Switching to this page fixed the slide headers.

A teacher explaining “quarters of the year” uses the four clusters so students see that Q1 contains winter months in the US, not a 13-week retail period.

Quarter-end dates

Civil quarter ends are March 31, June 30, September 30, and December 31. There is no March 32. Close processes that say “last Friday of the quarter” need the nth-weekday tool in addition to these end dates. This page gives the month span, not the last weekday.

ISO weeks can spill across quarter ends. ISO week 1 may begin in December of the prior year, which is civil Q4 of that prior year, not Q1. Use week number 2026 when a KPI is ISO-week based rather than civil-quarter based.

Leap Q1

Only Q1 changes length in a leap year (90 versus 91 days). Q2–Q4 stay the same day counts. Comparisons of Q1 year over year should mention leap day when February 29 sits in the quarter.

Century non-leap years keep Q1 at 90 days even if the year is divisible by 4 but not 400.

Limits

No automatic revenue split, no 13-week restatement, no fiscal relabeling. Screenshot the clusters. For a 12-month civil year without quarter grouping, use the custom calendar generator.

Date ranges that are not aligned to quarter starts belong on the date-range calendar, which touches whatever months the span covers, including a span from February 10 to April 2 that is not a quarter.

Board slides and even-quarter myths

Q1 is shorter than Q3 in day count even in leap years (91 versus 92). Saying four even quarters of ninety-one days is false. Footnote day counts on quarterly revenue slides when the audience might divide by ninety. 2026 Q1 uses that year’s February length.

Sales contests that run “Q4” meaning October–December are civil Q4 here. Contests that run “Q4” meaning the last thirteen retail weeks are not. Ask which system the contest memo uses before printing these month clusters as the contest map.

Close calendars

Civil quarter close is midnight at the end of March 31, June 30, September 30, and December 31 in the organization’s time zone, which this page does not encode. The grids show the last civil day. Last business day before that date needs a workday or holiday overlay if the 31st is a Saturday.

Leap Q1 on a printed packet

When Q1 includes February 29, the March grid still starts on the weekday after the 29th, not after the 28th. People reprinting last year’s Q1 packet in a leap year will have March wrong even if they remember to add a 29th box. Generate 2026 Q1 instead of photocopying a common-year Q1 and drawing an extra cell.

Q2 never contains February, so leap day never lengthens Q2–Q4. Year-over-year Q2 day counts are stable. Q1 is the only cluster that needs a leap footnote on the packet cover.