This date difference calculator counts the calendar days from a start date up to, but not including, an end date. January 1 through the following January 1 is the length of that year. January 1 to December 31 of the same non-leap year is 364 days, because December 31 has not yet reached the next January 1.
The count includes weekends and holidays. It does not care which date you enter first, because it uses the absolute difference. It also does not add a day for "inclusive" counting. If you need the number of calendar dates from the start through the end, add one to the result. The same start and end date produces 0, while an inclusive count of that single date is 1.
What the headline does not do is drop Saturdays and Sundays. The calendar year 2026, Thursday 1 January through Thursday 31 December, has 365 dates: 52 Saturdays, 52 Sundays, and 261 weekdays. The calculator still shows 364 elapsed days from 1 January to 31 December, because that figure is the year minus the end date, not the year minus the weekends. 261 weekdays is a different question, answered by listing the dates. This page now states those 2026 counts so the elapsed number is not mistaken for a count of working days.
How to use this calculator
- Enter the start date and the end date. Order does not change the result.
- Press Calculate. The headline is the elapsed day count.
- Read the week line as the day count divided by 7, not as a count of calendar weeks.
- Add one yourself if your deadline should include both the start date and the end date.
How elapsed days between dates are counted
Each date is treated as a calendar day, and the calculator takes the absolute number of days between them. The time of day is not an input. A span that crosses a leap day includes February 29, so 1 January 2024 to 31 December 2024 is 365 elapsed days, one more than the same span in 2026.
The second line divides that day count by 7 and rounds to at most two decimal places. It is not "how many Mondays" and it is not a count of Sunday-to-Saturday weeks. 364 divided by 7 is exactly 52, so the line reads "Approximately 52 weeks." 90 divided by 7 is about 12.857, shown as "Approximately 12.86 weeks."
Swapping the two dates does not change the number. A project that runs from April back to January is the same length as January to April. If you need a signed "how many days until" versus "how many days since," you have to look at which date is later yourself.
The 90 elapsed days from 15 January 2026 to 15 April 2026 are the 90 dates after 15 January up to and including 15 April. Fifteen January is a Thursday and 15 April is a Wednesday. Those 90 dates contain 13 Saturdays, 13 Sundays, and 64 weekdays. The calculator still reports 90 days and about 12.86 weeks. It does not report 64. A deadline that moves only on weekdays needs that second count, and this page prints it for the worked example so the two questions stay distinct. It still has no holiday list, so a weekday that is a public holiday remains inside the 64.
Formula
Elapsed days = absolute calendar-day difference between the two dates Inclusive day count = elapsed days + 1 Weeks shown = elapsed days / 7, rounded to at most two decimals
Inclusive counting is the rule many deadlines want. A rental from 1 March through 3 March covers three dates (the 1st, 2nd, and 3rd) and only two elapsed midnights. This calculator shows the elapsed 2 if you enter those dates, not the inclusive 3. Add one when the end date counts as a day you occupy or a day the task is still due.
The week line uses the elapsed count, not the inclusive count. If you add one for an inclusive span, divide that new total by 7 yourself. The calculator will not do the inclusive version for you.
Worked day-count examples
A non-leap year and a leap year
Start 1 January 2026, end 31 December 2026. 2026 is not a leap year. The calculator shows 364 days and "Approximately 52 weeks." The inclusive count of every date in 2026 is 365, which is 364 plus one. The 52 weeks is 364 / 7 exactly, so no decimal appears.
Start 1 January 2024, end 31 December 2024. 2024 is a leap year, and February 29 falls inside the span. The calculator shows 365 days and "Approximately 52.14 weeks." The inclusive count is 366. The extra day compared with 2026 is the leap day, not a different counting rule.
A 90-day span and the length of February
Start 15 January 2026, end 15 April 2026. The calculator shows 90 days and "Approximately 12.86 weeks." Ninety divided by 7 is 12.857…, and the week line stops at two decimal places. An inclusive count of 15 January through 15 April is 91 dates. Of the 90 dates after the start and through the end, 13 are Saturdays, 13 are Sundays, and 64 are weekdays. The week line is not that 64, and it is not 64 divided by 5.
Start 1 February 2026, end 1 March 2026. The calculator shows 28 days and "Approximately 4 weeks." 2026 is not a leap year, so February has 28 days, and 28 / 7 is 4. The same inputs in 2024 would include February 29 and show 29 days. The end date of 1 March is the day the span reaches March, not an extra day added on top of February.
The same date twice
Start and end both 1 March 2026. The calculator shows 0 days and "Approximately 0 weeks." There is no midnight between a date and itself.
If a form asks "how many days does this one-day event last?" the inclusive answer is 1, not the 0 this tool shows. Add one for that question. If a form asks "how many nights from arrival on 1 March to departure on 1 March," zero is the right hotel-night count, and the calculator already shows it.
Elapsed days versus an inclusive count
| Start | End | This calculator | Week line | Inclusive count |
|---|---|---|---|---|
| 1 Jan 2026 | 31 Dec 2026 | 364 days | Approximately 52 weeks. | 365 |
| 1 Jan 2024 | 31 Dec 2024 | 365 days | Approximately 52.14 weeks. | 366 |
| 15 Jan 2026 | 15 Apr 2026 | 90 days | Approximately 12.86 weeks. | 91 |
| 1 Feb 2026 | 1 Mar 2026 | 28 days | Approximately 4 weeks. | 29 |
| 1 Mar 2026 | 1 Mar 2026 | 0 days | Approximately 0 weeks. | 1 |
Weekends, holidays, and time zones
Weekends are included. A span of 14 elapsed days always shows 14 days even if ten of them are working days. For the full calendar year 2026 the dates themselves are 261 weekdays, 52 Saturdays, and 52 Sundays, 365 in all. The elapsed headline from 1 January to 31 December is still 364, because 31 December is the end date of an exclusive count, and that end date happens to be a Thursday. Subtracting the 104 weekend dates from 365 does not produce 364. The form still has no holiday switch, so those 261 weekdays still include any public holiday that falls on Monday through Friday.
The week figure is a decimal length, not a calendar-week count. "Approximately 12.86 weeks" does not mean twelve weeks and a particular weekday. Divide by 7 yourself if you want a quotient and a remainder: 90 days is 12 weeks and 6 days.
Dates are whole civil dates. The calculator does not apply a time of day, and the difference does not depend on which time zone you are in. Historical calendar reforms and dates far outside the modern Gregorian range are not a goal of this tool.
Frequently asked questions
Are both the start date and the end date counted?
The calculator counts elapsed days between them, so the end date is not an extra included day. Add one for an inclusive count. 1 January 2026 to 31 December 2026 shows 364 days, and the inclusive count of those dates is 365.
Does the day count include weekends?
Yes. Every civil day in the span counts, including Saturdays, Sundays, and holidays. The tool does not remove them from the headline. In the 15 January 2026 to 15 April 2026 example the headline is 90 days, of which 13 are Saturdays, 13 are Sundays, and 64 are weekdays. The calendar year 2026 has 52 Saturdays, 52 Sundays, and 261 weekdays.
What if I swap the start and end dates?
The result stays the same. The calculator uses the absolute difference, so it does not show a negative number when the end is earlier than the start.
How does a leap year change the count?
February 29 is a day when it falls strictly inside the span. 1 January to 31 December is 365 elapsed days in leap year 2024 and 364 elapsed days in 2026. 1 February to 1 March is 29 days in 2024 and 28 days in 2026.
Is the week line a count of calendar weeks?
No. It is the elapsed day count divided by 7, shown with at most two decimal places. 90 days displays as approximately 12.86 weeks, which is 12 weeks and 6 days if you want a remainder instead.
How many weekdays are in the 2026 calendar year?
261. The year has 365 dates, Thursday 1 January through Thursday 31 December, with 52 Saturdays and 52 Sundays. This calculator’s elapsed count from 1 January to 31 December is 364, not 261. The 364 figure keeps the weekends and drops the end date from an inclusive year count. It is not a business-day total, and the 261 weekdays still include public holidays.
Related ClearCalc pages
- US business days calculator Inclusive weekdays, with the 2026 federal holidays removed. The 364 elapsed days on this page are not those 250 business days.
- Exact age calculator Completed years, months, and days from a birthday. It borrows month lengths instead of counting every elapsed day.
- Hourly to salary calculator Turns an hourly rate and a number of weeks into annual pay. It does not count the days between two dates.