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Business Day Calculator

Business Days in September 2029

September 2029 has 19 business days under the US federal holiday calendar. September 2029 contains one US federal holiday. The month covers 30 calendar days, of which 10 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

19

Calendar Days

30

Weekend Days

10

Holidays

1

Work Weeks

3.8

September 2029 business day calendar
SunMonTueWedThuFriSat
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3
Labor Day
4
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8
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10
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Holidays in September 2029

Mon, Sep 3Labor Day

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 2029. Useful for shift scheduling, weekly recurring billing, and any rota that depends on a specific day of the week landing in-month.

DayCount
Monday4
Tuesday4
Wednesday4
Thursday4
Friday4
Saturday5
Sunday5

Business Days in September 2029 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.

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 2029 Compares

September 2028 had 20 business days, so September 2029 has 1 fewer working day year over year. On the surrounding months, August 2029 has 23 business days and October 2029 has 23. Looking forward, September 2030 will have 21 business days under the same federal holiday calendar.

Using This Calculator

A receivables analyst running a Net 30 portfolio uses the 19-business-day count in September 2029 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 2029, 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.

Frequently Asked Questions

How many business days are in September 2029?
September 2029 has 19 business days under the US federal holiday calendar. The month spans 30 calendar days, of which 10 fall on Saturday or Sunday and 1 is a federal holiday that lands on a weekday. The remaining 19 weekdays are countable as business days for invoicing, SLA windows, and contract math.
Are there any holidays in September 2029?
September 2029 contains one US federal holiday: Labor Day on Monday, September 3. Federal offices, the Federal Reserve, and US capital markets close on each of these days. State holidays and bank-specific closures may add additional non-working days for narrower contract definitions.
How does September 2029 compare to September 2028?
September 2028 had 20 business days, so September 2029 has 1 fewer working day year over year. The shift is driven by where weekends and federal holidays fall on the calendar in each year, not by any change in the number of holidays themselves. September 2029 starts on a Saturday and September 2028 started on a Friday, which determines how many of each weekday land in-month.
Why does the business-day count vary year to year?
Two things shift the monthly count. First, the day of the week the first of the month lands on changes the count of each weekday: a 31-day month starting on a Friday produces five Fridays, five Saturdays, and five Sundays, while one starting on a Monday produces five Mondays, five Tuesdays, and five Wednesdays. Second, federal holidays anchored to a fixed date (Independence Day, Veterans Day, Christmas Day) shift their weekday across years; some years the holiday lands on a weekend and the observance moves to the adjacent Friday or Monday, which keeps the business-day count steady but changes which weekday is excluded.
What if I need business days for a different country?
Use the country selector in the calculator above, or visit the dedicated country pages for the United Kingdom, Canada, Australia, India, the Philippines, France, Germany, Japan, Mexico, or Singapore. Each calculator excludes that country's national public holidays. The country comparison table further down this page shows the September 2029 business-day count under each of the eleven supported holiday calendars side by side.

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