The year splits into four calendar quarters of three months each: Q1 Jan–Mar, Q2 Apr–Jun, Q3 Jul–Sep, Q4 Oct–Dec. This calculator finds the quarter for any date, with its start and end dates, the day into the quarter, and the days remaining.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: Gregorian calendar quarters, recomputed in code.
How it's worked out
Each quarter begins on the first of its first month and ends on the last of its third. Quarter lengths aren't equal: in a common year Q1 has 90 days, but 91 in a leap year because February gains a day; Q2 always has 91 days, and Q3 and Q4 each have 92. The day into the quarter counts from its first day, and the days remaining is the quarter length minus that.
Worked examples
July 4, 2024:
November 15, 2025:
March 1, 2024 (leap year):
So a mid-quarter date like Nov 15 sits exactly halfway through Q4, with 46 days gone and 46 to go. The calculator returns the quarter, its range, and both counts at once.
Frequently Asked Questions
Q1 Jan–Mar, Q2 Apr–Jun, Q3 Jul–Sep, Q4 Oct–Dec — three months each.
Divide the month number by 3 and round up. March → Q1, July → Q3, November → Q4.
Q1 90 (91 leap), Q2 91, Q3 92, Q4 92.
Calendar quarters start in January. Fiscal years may start elsewhere, shifting the quarters.
Quarter length minus day-into-quarter. Jul 4 → day 4 of 92 → 88 remaining.