There are 122 days between 1 September 2026 and 31 December 2026 — 88 weekdays, 34 weekend days and 83 business days (weekdays minus US federal holidays). The range covers 4 months, from Tuesday, 1 September 2026 (Tuesday) to Thursday, 31 December 2026 (Thursday). This page gives the exact count, the month-by-month breakdown, and how the count is worked out.

Try the tool: Days Between Dates Calculator — count the days, weeks and months between any two dates.

Try the tool: Business Days Calculator — count the business days in this range, with your own holidays added.

The count

Count Value
Total days (1 September to 31 December 2026, inclusive) 122
Weekdays (Monday–Friday) 88
Weekend days 34
Business days (weekdays minus federal holidays) 83
Full weeks 17 (plus 3 days)

The count is inclusive: it counts both the first day (1 September) and the last day (31 December). The days between dates calculator uses the standard convention of counting the days you add to the start date to reach the end date, which for this range gives 121 days — one less than the inclusive count, because the start day itself is not counted. Both conventions are correct; they answer slightly different questions, and the difference is always exactly one day.

Month-by-month breakdown

Month Days Weekdays Weekends Business days
September 2026 30 22 8 21
October 2026 31 22 9 21
November 2026 30 21 9 19
December 2026 31 23 8 22
Total 122 88 34 83

Working weeks in the range

Every working week in the range, with its business days:

Week starting Days Business days
31 August 2026 1 September 2026 – 6 September 2026 4
7 September 2026 7 September 2026 – 13 September 2026 4
14 September 2026 14 September 2026 – 20 September 2026 5
21 September 2026 21 September 2026 – 27 September 2026 5
28 September 2026 28 September 2026 – 4 October 2026 5
5 October 2026 5 October 2026 – 11 October 2026 5
12 October 2026 12 October 2026 – 18 October 2026 4
19 October 2026 19 October 2026 – 25 October 2026 5
26 October 2026 26 October 2026 – 1 November 2026 5
2 November 2026 2 November 2026 – 8 November 2026 5
9 November 2026 9 November 2026 – 15 November 2026 4
16 November 2026 16 November 2026 – 22 November 2026 5
23 November 2026 23 November 2026 – 29 November 2026 4
30 November 2026 30 November 2026 – 6 December 2026 5
7 December 2026 7 December 2026 – 13 December 2026 5
14 December 2026 14 December 2026 – 20 December 2026 5
21 December 2026 21 December 2026 – 27 December 2026 4
28 December 2026 28 December 2026 – 31 December 2026 4

The first and last weeks

The first week of the range, day by day:

Date Day of the week
1 September 2026 Tuesday
2 September 2026 Wednesday
3 September 2026 Thursday
4 September 2026 Friday
5 September 2026 Saturday
6 September 2026 Sunday
7 September 2026 Monday

And the last week:

Date Day of the week
25 December 2026 Friday
26 December 2026 Saturday
27 December 2026 Sunday
28 December 2026 Monday
29 December 2026 Tuesday
30 December 2026 Wednesday
31 December 2026 Thursday

How the count is worked out

The range is counted month by month, because the months have different lengths. September has 30 days, October has 31 days, November has 30 days, December has 31 days — 122 days in total. The weekdays are counted from the real calendar: each month starts on a different weekday, so the number of Saturdays and Sundays differs from month to month, and the table above shows the exact split. The business days subtract the US federal holidays that fall on weekdays in the range: Labor Day (7 September), Columbus Day (12 October), Veterans Day (11 November), Thanksgiving Day (26 November), Christmas Day (25 December).

The range in the year

The range from 1 September to 31 December 2026 starts 243 days into the year and leaves 0 days after it ends — 365 days in the year in total, since 2026 is not a leap year. It spans quarters Q3 and Q4 of 2026, and it begins in autumn in the Northern Hemisphere (the seasons are reversed in the Southern Hemisphere).

The federal holidays inside the range are Labor Day (7 September 2026), Columbus Day (12 October 2026), Veterans Day (11 November 2026), Thanksgiving Day (26 November 2026), Christmas Day (25 December 2026). Each one that falls on a weekday costs a business day — that is why the business day count (83) is lower than the weekday count (88). If you are planning a project or a deadline across this range, the holidays are the days to check first, before you promise a date.

The same range in other years

Year Total days Weekdays Business days
2025 122 88 83
2026 122 88 83
2027 122 88 84

The range is 122 days in 2026 and the same number of days in the adjacent years, except where February is involved: a leap year adds one day to any range that includes February. This range does not include February, so the total is the same every year — only the weekday split changes.

Frequently asked questions

How many days are there between 1 September and 31 December 2026?

122 days inclusive (121 days by the standard days-between convention, which does not count the start day). Of those, 88 are weekdays and 83 are business days.

How many business days are in this range?

83 business days — 88 weekdays minus the federal holidays that fall on weekdays in the range.

How many weeks is 122 days?

17 weeks and 3 days.

How do you count days between two dates?

Count the days you add to the start date to reach the end date. The days between dates calculator does it for any two dates, and shows the answer in days, weeks and months.

What is the same range in 2027?

See the table above for the 2027 figures — the total is the same unless the range includes February in a leap year.

Sources

  • IANA Time Zone Database, via Node.js Intl (Intl.DateTimeFormat with timeZone) — offsets, daylight saving dates and local times in this article were worked out from the IANA database, not typed from memory.
  • TimeFlow's own time-zone data (data/cities.ts, data/dst.ts), computed from the IANA database.
  • US federal holiday rules (5 U.S.C. § 6103): the holidays subtracted in the business day count are the eleven federal holidays, on the dates set by law.
  • TimeFlow's days between dates calculator and business days calculator — the live tools behind the counts on this page.
  • Time-zone and daylight saving rules are set by governments and can change. For flights, deadlines and meetings that cannot move, confirm the time with an official source.