Days Between Dates Calculator

Inclusive and exclusive counting

There are two common ways to count the days between dates, and they differ by one.

• Exclusive (the default). Counts the days you move forward to get from the start to the end. From a Monday to the Friday of the same week is 4 days. This is the right count for gaps, countdowns and “how many days since”.
• Inclusive. Counts every day in the range, including both the first and the last. Monday to Friday is then 5 days. Use this when each day is occupied, such as the length of a festival or the number of days of leave you are taking.

Most disagreements over day counts come from mixing these two methods. If a contract or policy specifies a number of days, check whether it says both days count.

How to calculate days between two dates by hand

To check a result without the calculator, count to the end of each month and then add the rest. Take Monday, March 2, 2026 to Friday, July 17, 2026.

1. Finish the first month. March has 31 days, so moving from March 2 to April 1 takes 31 − 2 + 1 = 30 days.
2. Add the full months in between. April (30), May (31) and June (30) add 91 days, bringing you to July 1 after 121 days.
3. Add the days in the last month. From July 1 to July 17 is 16 days, for a total of 137 days.

That is the exclusive count. Counting both March 2 and July 17 gives 138 days. To count weekdays, split the total into full weeks: 137 days is 19 weeks and 4 days. The 19 full weeks contain 19 × 5 = 95 weekdays, and the 4 extra days, starting from Monday, are Monday to Thursday, all weekdays. That gives 99 weekdays and 38 weekend days.

Weekdays (business days) between dates

The weekdays figure counts Mondays to Fridays in the range, and the weekend figure counts Saturdays and Sundays. Together they always add up to the total days. The same counting rule applies here as for the main result: the start date is included, and the end date is only included when the checkbox is ticked.

Public holidays are counted as ordinary weekdays. To get working days, take the weekday total and subtract any holidays that apply to you.

Years, months and days between dates

The result in years, months and days counts whole calendar months from the start date, then the days left over. Because months vary in length, the same number of days can be a different number of months depending on where the range falls. A 31-day period starting on February 1 covers one month and 3 days in a common year, but a 31-day period starting on March 1 is exactly one month.

Days from Sunday, October 4, 2026

The table below shows how far some common dates are from Sunday, October 4, 2026, the date this page was last updated. For any other starting point, enter it in the calculator. The exclusive count is the number of days you wait; the inclusive count adds the end date.

Where day counts are used

• Deadlines and notice periods. Contracts, leases and job offers often give a number of days to respond or to leave. Count from the date the period starts and check whether the wording includes the last day.
• Project planning. The weekdays figure gives a rough count of working days in a phase. Subtract public holidays and planned time off for a more realistic figure.
• Travel and visas. Trip lengths and permitted stays are usually counted in days. Immigration rules often count both the arrival and departure days as days of stay, which is an inclusive count; check the official rules for the country you are visiting.
• Days since an event. Anniversaries, streaks and “days without an incident” counters are exclusive counts from the event date to today.
• Billing and interest periods. Some charges are worked out per day. The simple interest calculator is useful when a rate is applied over a number of days.

Tips and common mistakes

• Mixing inclusive and exclusive counts. A booking from June 1 to June 14 is 13 nights but 14 days of use. Decide which one you need before comparing numbers.
• Treating weekdays as working days. The weekday count does not remove public holidays, shutdowns or leave.
• Assuming every month is 30 days. Estimating from an average month length can put a deadline a day or two out. Count calendar days instead.
• Forgetting the leap day. Any range that includes February 29, such as November 2027 to March 2028, has one more day than the same range in a common year.
• Expecting time zones to count. The calculator compares calendar dates only. If two places are on different dates at the same moment, use the date that applies to the rule you are following.

Glossary

• Exclusive count. Days from the start date up to, but not including, the end date.
• Inclusive count. Days including both the start and end dates; always one more than the exclusive count.
• Weekday. Monday to Friday. Not the same as a business day if holidays apply.
• Business day. A working day for a particular organization, usually a weekday that is not a public holiday.

Other ways to work with dates

For a person’s age in years, months and days, the age calculator uses the same method and adds the next birthday. To go the other way and find the date a given number of days from a start date, use the date calculator. For hours within a single day, use the hours calculator.