Business Days in September 2025
September 2025 has 21 business days under the US federal holiday calendar. September 2025 contains one US federal holiday. The month covers 30 calendar days, of which 8 fall on a weekend. That count drives invoice due dates, payroll cycles, project sprint planning, and any contract that defines deadlines as a number of working days.
Business Days
21
Calendar Days
30
Weekend Days
8
Holidays
1
Work Weeks
4.2
| Sun | Mon | Tue | Wed | Thu | Fri | Sat |
|---|---|---|---|---|---|---|
1 Labor Day | 2 | 3 | 4 | 5 | 6 wknd | |
7 wknd | 8 | 9 | 10 | 11 | 12 | 13 wknd |
14 wknd | 15 | 16 | 17 | 18 | 19 | 20 wknd |
21 wknd | 22 | 23 | 24 | 25 | 26 | 27 wknd |
28 wknd | 29 | 30 |
Holidays in September 2025
The first Monday of September. Federal offices, the Federal Reserve, and US equity and bond markets close. It marks the unofficial end of summer and the beginning of the post-Labor-Day project cadence; many B2B vendors restart pipeline work the Tuesday after.
Day-of-Week Distribution
The count of each weekday in September 2025. Useful for shift scheduling, weekly recurring billing, and any rota that depends on a specific day of the week landing in-month.
| Day | Count |
|---|---|
| Monday | 5 |
| Tuesday | 5 |
| Wednesday | 4 |
| Thursday | 4 |
| Friday | 4 |
| Saturday | 4 |
| Sunday | 4 |
Business Days in September 2025 by Country
Working-day counts vary by country because each country observes its own public holidays. The table below covers all eleven holiday calendars supported on this site.
| Country | Business Days | Holidays this month |
|---|---|---|
| 🇺🇸United States | 21 | Labor Day |
| 🇬🇧United Kingdom | 22 | None |
| 🇨🇦Canada | 20 | Labour Day, National Day for Truth and Reconciliation |
| 🇦🇺Australia | 22 | None |
| 🇮🇳India | 22 | None |
| 🇵🇭Philippines | 22 | None |
| 🇫🇷France | 22 | None |
| 🇩🇪Germany | 22 | None |
| 🇯🇵Japan | 20 | Respect for the Aged Day, Autumnal Equinox Day |
| 🇲🇽Mexico | 21 | Día de la Independencia |
| 🇸🇬Singapore | 22 | None |
Notable September Deadlines
September 15 is the extended partnership and S-corp filing deadline (Form 1065 and Form 1120-S). Calendar-year C-corps make their Q3 estimated tax payment the same day. The federal fiscal year ends September 30, so government contractors and grant-funded organizations face year-end milestone deliverables in the last week.
How September 2025 Compares
September 2024 had 20 business days, so September 2025 has 1 more working day year over year. On the surrounding months, August 2025 has 21 business days and October 2025 has 23. Looking forward, September 2026 will have 21 business days under the same federal holiday calendar.
Using This Calculator
A receivables analyst running a Net 30 portfolio uses the 21-business-day count in September 2025 to project cash collections by Friday of each week and to flag invoices whose due dates land on the holidays listed above. A project manager scoping a sprint that starts on the first business day of September uses the calendar grid to slot stand-ups, design reviews, and customer demos onto live working days rather than weekends. A specialty contractor billing time and materials uses the day-of-week distribution to see how many Mondays and Fridays fall in September 2025, which matters for crews who set installation appointments at the start and end of each week and skip Tuesday-to-Thursday for travel-heavy jobs.
For informational purposes only
This calculator provides general estimates based on business day counting rules. It does not constitute legal advice. Deadlines in legal, regulatory, or contractual matters may be subject to jurisdiction-specific rules, court orders, or statutory exceptions. Always verify critical deadlines with a qualified professional.