Date Difference Calculator
The exact gap between two dates in days, weeks and weekdays, plus a quick add-or-subtract-days tool for deadlines.
How the difference is calculated
The calculator counts actual calendar days between your two dates, correctly handling leap years, months of different lengths, and daylight saving transitions. The years-months-days breakdown follows the same convention used for tenure and age: it moves forward whole years first, then whole months, then the remaining days.
Should you include the end date?
It depends on what you are measuring. For "how many days until my exam", exclude it: from Monday to Friday is 4 days of waiting. For "how many days was I on this project" or hotel-style counting where both boundary days count, include it: Monday to Friday becomes 5 billable days. The checkbox lets you switch instantly, and notice period or rent calculations usually specify which convention applies.
Weekdays and working days
The weekday count includes every Monday to Friday in the range and excludes Saturdays and Sundays. Public holidays vary by country and state, so subtract the holidays relevant to you from the weekday figure. For example, a 30-day span with 22 weekdays and 2 public holidays has 20 working days.
Everyday uses
People use this tool to count days until a wedding or exam, compute notice periods and probation ends, check visa stay limits (many visas cap days within a rolling window), work out interest day-counts on deposits, and settle the classic office debate about whether the deadline is 45 or 46 days away. The add-or-subtract tool answers the reverse question: what date is 90 days from today?
Worked example: a notice period
Suppose you resign on 10 March and your contract requires 60 days of notice. Set 10 March as the base date in the add-days tool and add 60: your last working day is 9 May. Now check the difference tool between the two dates with "include end date" on and you will see 61 days, which is why HR teams specify whether the resignation day itself counts. This calculator lets you test both interpretations in seconds and settle the conversation with a screenshot.
Date formats and ambiguity
03/04/2026 means 3 April in India and the UK but 4 March in the US. The date pickers here remove that ambiguity entirely: you select from a calendar, and the result names the month and weekday explicitly, so the output can be shared across countries without misreading.
Frequently asked questions
How many days are between two dates?
Pick the start and end date above. The tool shows total days, the years-months-days breakdown, weeks, weekdays and hours instantly, handling leap years automatically.
Does the calculator count leap years correctly?
Yes. It uses real calendar arithmetic, so 29 February is counted in leap years (2024, 2028) and skipped in others. Century years like 2100 are correctly treated as non-leap years.
How do I calculate working days excluding holidays?
The tool excludes weekends for you (the weekdays figure). Public holidays differ by country and even by state, so subtract your local holidays from the weekday count.
What date is 90 days from today?
Use the add-or-subtract section: set today as the base date, enter 90, choose Add, and the exact calendar date appears, including the day of the week.