September 2025 CalendarSeptember 2025

About September 2025

September's name comes from the Latin 'septem' ('seven'), reflecting its position as the seventh month in the earliest Roman calendar — a name that was never updated even after January and February were added to the front, pushing it to ninth place. The same renumbering-without-renaming quirk shows up in October, November, and December too, each still carrying a Latin numeral name one full step behind its true place in the year. The Northern Hemisphere's autumn equinox falls around September 22-23, while the Southern Hemisphere marks its spring equinox on the same date. Sapphire is the month's traditional gemstone, the aster and morning glory its flowers, and Virgo hands off to Libra around the 22nd or 23rd. No later calendar reform has ever bothered correcting these four numeral names, leaving the mismatch permanently baked into the modern calendar.

The US observes September as National Preparedness Month, established following the aftermath of the September 11, 2001 attacks to encourage emergency-readiness planning nationwide, coordinated annually by federal emergency management agencies.

The United Nations General Assembly holds its main annual session opening in September, drawing world leaders to New York for a period of intense diplomatic activity.

September 2025: 22 weekdays, 8 weekend days.

September 2025: first day Monday, last day Tuesday — September runs 30 days total.

In September, the 13th lands on Saturday this 2025.

September 2025 contains 4 complete Saturday-to-Sunday weekends.

September 2025: first Monday 1st, first Sunday 7th.

September 2025: third Friday is the 19th.

2025, September: day 244 to 273 of 2025 (Q3).

September 2025 ends with 92 days left in 2025.

September 2025: 1 holiday tracked.

Holidays in September 2025

• Labor Day (US) — Monday, September 1

Nearby calendars

Browse every month on the Calendar index, or find days-in-month and week-number math with the Days in a Month and Week Number Calculator tools.