There are 122 days between 1 September 2027 and 31 December 2027 — 88 weekdays, 34 weekend days and 84 business days (weekdays minus US federal holidays). The range covers 4 months, from Wednesday, 1 September 2027 (Wednesday) to Friday, 31 December 2027 (Friday). 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 2027, inclusive) | 122 |
| Weekdays (Monday–Friday) | 88 |
| Weekend days | 34 |
| Business days (weekdays minus federal holidays) | 84 |
| 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 2027 | 30 | 22 | 8 | 21 |
| October 2027 | 31 | 21 | 10 | 20 |
| November 2027 | 30 | 22 | 8 | 20 |
| December 2027 | 31 | 23 | 8 | 23 |
| Total | 122 | 88 | 34 | 84 |
Working weeks in the range
Every working week in the range, with its business days:
| Week starting | Days | Business days |
|---|---|---|
| 30 August 2027 | 1 September 2027 – 5 September 2027 | 3 |
| 6 September 2027 | 6 September 2027 – 12 September 2027 | 4 |
| 13 September 2027 | 13 September 2027 – 19 September 2027 | 5 |
| 20 September 2027 | 20 September 2027 – 26 September 2027 | 5 |
| 27 September 2027 | 27 September 2027 – 3 October 2027 | 5 |
| 4 October 2027 | 4 October 2027 – 10 October 2027 | 5 |
| 11 October 2027 | 11 October 2027 – 17 October 2027 | 4 |
| 18 October 2027 | 18 October 2027 – 24 October 2027 | 5 |
| 25 October 2027 | 25 October 2027 – 31 October 2027 | 5 |
| 1 November 2027 | 1 November 2027 – 7 November 2027 | 5 |
| 8 November 2027 | 8 November 2027 – 14 November 2027 | 4 |
| 15 November 2027 | 15 November 2027 – 21 November 2027 | 5 |
| 22 November 2027 | 22 November 2027 – 28 November 2027 | 4 |
| 29 November 2027 | 29 November 2027 – 5 December 2027 | 5 |
| 6 December 2027 | 6 December 2027 – 12 December 2027 | 5 |
| 13 December 2027 | 13 December 2027 – 19 December 2027 | 5 |
| 20 December 2027 | 20 December 2027 – 26 December 2027 | 5 |
| 27 December 2027 | 27 December 2027 – 31 December 2027 | 5 |
The first and last weeks
The first week of the range, day by day:
| Date | Day of the week |
|---|---|
| 1 September 2027 | Wednesday |
| 2 September 2027 | Thursday |
| 3 September 2027 | Friday |
| 4 September 2027 | Saturday |
| 5 September 2027 | Sunday |
| 6 September 2027 | Monday |
| 7 September 2027 | Tuesday |
And the last week:
| Date | Day of the week |
|---|---|
| 25 December 2027 | Saturday |
| 26 December 2027 | Sunday |
| 27 December 2027 | Monday |
| 28 December 2027 | Tuesday |
| 29 December 2027 | Wednesday |
| 30 December 2027 | Thursday |
| 31 December 2027 | Friday |
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 (6 September), Columbus Day (11 October), Veterans Day (11 November), Thanksgiving Day (25 November).
The range in the year
The range from 1 September to 31 December 2027 starts 243 days into the year and leaves 0 days after it ends — 365 days in the year in total, since 2027 is not a leap year. It spans quarters Q3 and Q4 of 2027, 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 (6 September 2027), Columbus Day (11 October 2027), Veterans Day (11 November 2027), Thanksgiving Day (25 November 2027), Christmas Day (25 December 2027). Each one that falls on a weekday costs a business day — that is why the business day count (84) 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 |
|---|---|---|---|
| 2026 | 122 | 88 | 83 |
| 2027 | 122 | 88 | 84 |
| 2028 | 122 | 86 | 82 |
The range is 122 days in 2027 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 2027?
122 days inclusive (121 days by the standard days-between convention, which does not count the start day). Of those, 88 are weekdays and 84 are business days.
How many business days are in this range?
84 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 2028?
See the table above for the 2028 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.DateTimeFormatwithtimeZone) — 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.