Days Between Dates Calculator
The calculator counts how many days lie between two dates and converts the answer into weeks, calendar years with months, and business days.
The "count the last day" switch settles a familiar argument: a period running from the 1st to the 10th is nine days of difference but ten days inclusive.
Days between the dates
243
January 1, 2026 → September 1, 2026
Weeks and days
34 w 5 d
In calendar terms
0 y 8 mo 0 d
Business days (Mon–Fri)
173
Public holidays are ignored: only Saturdays and Sundays are excluded. · Hours: 5,832
What the calculator returns
- Calendar days — the plain difference, weekends and holidays included.
- Weeks and days — the same difference broken into sevens.
- Calendar terms — full years, months and days, the way service length and age are counted.
- Business days — Monday to Friday only, with no public holidays applied.
Difference or inclusive length
Nine days pass between 1 and 10 August: that is how many nights a hotel charges and how many days interest accrues. Counting the holiday itself gives ten days, because both end dates are occupied.
The rule is simple: a difference answers "how much time has passed", an inclusive count answers "how long does it last". Contracts and sick leave normally use the second one.
Days in typical periods
| Period | Calendar days | Business days |
|---|---|---|
| One week | 7 | 5 |
| Two weeks | 14 | 10 |
| A month (30 days) | 30 | about 22 |
| A quarter | 90–92 | about 65 |
| Half a year | 181–184 | about 130 |
| A year | 365 or 366 | about 261 |
About business days and holidays
The calculator excludes Saturdays and Sundays only. Public holidays, substitute days off and company rules differ by country and by year, and no universal calculation can cover them.
For contract deadlines or delivery windows, check the working calendar of the relevant country and year: a single holiday week can move the count by several days.
Frequently asked questions
How do I count the days between two dates?
Enter the start and end dates — the calculator shows the difference in days along with weeks, months and business days.
Should the last day be included?
Not for "how much time has passed". For a period that runs from one day through another inclusive, turn the switch on.
Are public holidays excluded from business days?
No. Only Saturdays and Sundays are removed, because holiday calendars depend on the country and the year.
What happens if the end date is earlier than the start date?
The calculator shows the absolute difference and notes that the dates are reversed.
Why doesn't the calendar result match days divided by 30?
Months hold between 28 and 31 days. The calendar count follows real months, while dividing by 30 is only a rough estimate.
Updated: 2026-08-09