Days between dates calculator
Calculate the number of days, weeks, months and working days between two dates. Free online date difference calculator.
Current for 2026Methodology →
Add or subtract days from a date
Enter a start date, choose a quantity of days, weeks or months to add (or subtract using a negative value), and get the result date instantly. The calculator handles leap years and varying month lengths correctly. Useful for payment deadlines, delivery dates, warranty expiry and travel planning.
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How we calculate the result date
For days: result = start + n. For weeks: result = start + n × 7. For months: the month shifts by n, keeping the same day number (if that day does not exist in the target month, the last day of that month is used). Leap years are handled automatically.
Example calculation
Start date: 1 January 2026, quantity: 30, unit: days → result: 31 January 2026. Another example: 31 January 2026 + 1 month → 28 February 2026 (February has 28 days in 2026).
Frequently asked questions
How do I add days to a date?
Enter the start date, type the number of days in the quantity field, select "days" as the unit, and the calculator shows the result date immediately.
Can I subtract days from a date?
Yes — enter a negative value in the quantity field (e.g. −14) to subtract 14 days from the start date.
How do I add weeks to a date?
Select "weeks" as the unit and enter the number of weeks. The calculator converts weeks to days (1 week = 7 days) and returns the correct result date.
How do I add months to a date?
Select "months" and enter the number of months. The calculator accounts for the actual length of each month, so adding 1 month to 31 January gives 28 or 29 February depending on the year.
Does the calculator handle leap years?
Yes. Adding 1 day to 28 February 2024 (a leap year) gives 29 February 2024; in a non-leap year it gives 1 March.
What is this calculator useful for?
Calculating payment due dates, delivery dates, warranty expiry, notice period end dates, document validity and travel planning.
How do I find the date 30 days from today?
Enter today's date as the start date, type 30 in the quantity field and select "days". The result date appears immediately.
What will the date be in 3 months?
Enter your start date, type 3 and select "months". The calculator accounts for the exact number of days in each month.
Does the result depend on the time zone?
No — the calculator works with dates only (year, month, day) and ignores hours and time zones. The result is always a Gregorian calendar date.
How do I find how many days have passed since a date?
To count elapsed days, use the "days between dates" calculator. This calculator is best suited for finding future or past dates.
The result is indicative. The calculator operates on dates without time zones and does not account for public holidays or working days.
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