How the difference is counted
By default the calculator counts the days from the start date up to the end date, without counting the end date itself. That is how durations such as "days until" or loan interest periods are normally measured. Tick Include the end date when both days count, for example leave from 1 to 5 March is 5 days.
Example
From 1 January 2026 to 28 September 2026 there are 270 days: 8 months and 27 days, or 38 weeks and 4 days. 192 of those days are weekdays.
Common uses
- Counting days for notice periods, rent agreements and warranties.
- Working out interest periods for loans, FDs and late payment charges.
- Project timelines and deadlines. For business days excluding holidays, use the Working Days Calculator.
- Pregnancy, visa stays and subscription periods.
Frequently asked questions
Does the calculator handle leap years?
Yes. It works with real calendar dates, so 29 February is counted in leap years.
How many days are there between two dates including both dates?
Tick "Include the end date". This adds one day to the count, so 1 to 10 March becomes 10 days instead of 9.
Results are for general information. Check important dates and figures against official sources.
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