Date Difference Calculator

How do you count the days between two dates?

Counting days between dates matters more often than you might think: notice periods, interest on a deposit, loan due dates, visa stays, project deadlines and legal limitation periods all depend on it. The main question is whether to count both the start and end dates, which changes the answer by one day.

This date difference calculator shows the gap between any two dates in years, months and days, and as total days, weeks and working days (Monday to Friday), with an option to include the end date.

How this calculator works

The difference between two dates is reported two ways, because both are useful. The calendar difference — years, months and days — is what contracts and notice periods use. The total day count is what you need for interest, penalties and deadlines.

Weekday and weekend counts are produced by walking the range day by day, so public holidays aside, the figure is exact rather than an approximation based on dividing by seven.

Formula

Total days = end date − start date      (+1 when both days are counted)
Calendar difference = whole years, then whole months, then leftover days
Weekdays = days in range that are not Saturday or Sunday

Worked example

1. From 1 April 2026 to 30 June 2026: 90 days between the dates, 91 if both are counted.
2. That is 2 months and 29 days in calendar terms, with 65 weekdays.

Common uses

• Notice periods and service length, where “both days inclusive” is the usual convention.
• Interest calculations: banks usually count the actual number of days the money was deposited, excluding the day of deposit or of withdrawal.
• Loan and bill due dates, and the grace period before a late fee applies.
• Visa and travel limits, which are normally counted in calendar days including arrival and departure.
• Project planning, where working days — excluding weekends and holidays — matter more than calendar days.

Assumptions & important notes

Frequently asked questions