Date Difference Calculator
Count the days, weeks, months and business days between two dates — or add a duration to a date.
Your details
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Days between
358 days
0 years, 11 months, 24 days
Includes your inputs, the full breakdown, and every row of the table.
Weeks
51.14
Business days
256
Weekend days
102
Months (approx)
11.76
- From
- Thursday, January 1, 2026
- To
- Friday, December 25, 2026
- Total days
- 358
- Calendar breakdown
- 0y 11m 24d
- Hours
- 8,592
What this means
- Business days here exclude Saturdays and Sundays but not public holidays, which vary by country and even by state.
- The calendar breakdown counts real months rather than thirty-day blocks, so it will not always match the total days divided by thirty.
How the date difference calculation works
Counting days between dates is one of those tasks that looks trivial until leap years, uneven month lengths and inclusive counting get involved. This calculator treats dates as whole days in UTC to avoid daylight saving shifting a result by one, which is a surprisingly common source of off-by-one errors in date arithmetic.
Two different answers are both legitimate depending on what you are measuring. The total day count is a simple subtraction and is what you want for interest, deadlines and age in days. The calendar breakdown into years, months and days respects the actual length of each month, which is why it will rarely equal the day count divided by thirty. Contracts and notice periods almost always mean the calendar version.
Frequently asked questions
Should I count both the start and end date?
It depends on the context, and this is where disputes come from. This calculator gives the difference, so a Monday to a Tuesday is one day. Notice periods and hotel stays often count inclusively, which would make that two days. Check which convention your contract uses before relying on the number.
Are public holidays excluded from business days?
No. The business day count here removes weekends only, because holidays differ by country, state and sometimes industry. For a legal or payroll deadline you will need to subtract the relevant holidays yourself.
How are leap years handled?
Automatically and correctly. The calculation works on actual calendar dates rather than assuming a 365-day year, so any 29 February falling inside your range is counted. This is why a year-long span can be either 365 or 366 days.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.