Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Find which calendar quarter (Q1-Q4) any date falls in.
Q3 2026
This tool maps any date to its calendar quarter -- Q1 (January-March), Q2 (April-June), Q3 (July-September), or Q4 (October-December) -- and shows that quarter's exact start and end dates. It uses the standard calendar-year quarter definition; businesses on a non-calendar fiscal year should offset the result accordingly.
Enter any date. The result shows its quarter label (e.g. "Q4 2026") along with the quarter's first and last calendar dates.
Quarter number = floor(month index / 3) + 1, where month index runs 0 (January) through 11 (December). The quarter's start date is the 1st of its first month, and its end date is the last day of its third month.
November 15, 2026 falls in Q4 2026 (October 1, 2026 - December 31, 2026).
For the ISO week number of a date, see the Week Number Calculator. For the day-of-year ordinal position, use the Day of Year Calculator.
Enter a date and read the quarter label together with its first and last dates. Because the label includes the year, it is ready to paste into a report heading or spreadsheet column. The start and end dates are useful when you need to set the boundaries of a query, a report window, or a reminder, since they are always the first day of the quarter's first month and the last day of its third month.
Boundary dates cause most quarter mistakes, so test them. A hypothetical invoice dated March 31, 2026 is in Q1, but the same invoice dated April 1, 2026 is in Q2, even though the dates are one day apart. Similarly, December 31 sits in Q4 of its own year, while January 1 starts Q1 of the next. For a leap-year check, a Q1 that ends March 31 has 91 days in a leap year and 90 in a common year, the only quarter whose length depends on it.
The tool reports calendar quarters only. If your organization's fiscal year starts in another month, you can translate by hand. Suppose a hypothetical fiscal year begins in July. Then July to September is fiscal Q1, October to December is fiscal Q2, January to March is fiscal Q3, and April to June is fiscal Q4. Use the calendar quarter shown here to identify the three-month block, then relabel it under your fiscal scheme. Also confirm how your company names the fiscal year, since some name it for the year in which it starts and others for the year in which it ends.
Quarter lookups help with sorting expenses for estimated payments, building quarterly review calendars, naming files and dashboards, and lining up contract renewal dates with a reporting period. For anything with tax or legal consequences, use this only as a calendar check and follow the official deadlines published by the relevant agency.
Calendar year (Q1 starting January 1) -- if your organization uses a different fiscal year start, shift the result by the appropriate number of quarters.
90 or 91 days for Q1 (depending on leap year), 91 for Q2, 92 for Q3, and 92 for Q4 -- quarters aren't exactly equal in length since months have different day counts.
Yes -- the year is taken directly from the entered date, so past and future years both work.
Q1 runs January 1 to March 31, Q2 April 1 to June 30, Q3 July 1 to September 30, and Q4 October 1 to December 31.
Find the calendar quarter here, then relabel that three-month block using your fiscal year start month, since the tool itself does not apply a fiscal offset.
They are made of whole months, and months have different lengths. Q1 has 90 or 91 days, Q2 has 91, and Q3 and Q4 have 92.
Reference: U.S. Department of Labor