How to Count the Days Between Two Dates

The basic calculation

To find the number of days between two dates, you subtract the earlier date from the later one. Computers store dates as a running count of time, so the difference comes out cleanly — no need to remember how many days are in each month or whether it’s a leap year.

Example. From March 1 to March 8 is 7 days. That matches the intuition that one week separates the two dates.

Inclusive vs. exclusive counting

Here’s the part that trips people up. “How many days between March 1 and March 8?” has two reasonable answers depending on what you’re really asking:

• Exclusive (the difference): 7 days. You’re measuring the gap — the number of nights, or how far apart the two dates sit.
• Inclusive (counting both ends): 8 days. You’re counting every calendar day that the period touches, including both the first and the last.

Neither is “more correct” — it depends on the question. A hotel stay from the 1st to the 8th is 7 nights (exclusive). A festival that runs “from the 1st through the 8th” lasts 8 days (inclusive). When a deadline or contract matters, check which convention applies before you rely on the number.

Date Math’s Between Dates tool reports the difference between the two dates. If your situation counts both endpoints, simply add one to the result.

Turning days into weeks

A raw day count like “94 days” is hard to picture. Breaking it into weeks helps: divide by 7 to get whole weeks, and the remainder is the leftover days. So 94 days is 13 weeks and 3 days. The Between Dates tool shows this breakdown automatically, and gives you a one-click “Copy sentence” button so you can paste a clean, human-readable result into an email or message.

Counting only business days

Sometimes the gap that matters is measured in working days, not calendar days. Turn on “Business days only” in the Between Dates tool and weekends are removed from the count; add “Exclude holidays” and you can drop public holidays for the U.S., U.K., Canada, or Australia too. The tool still shows the total calendar days alongside the business-day count, so you can see both at a glance. For a deeper look at how that works, see the guide to business days.

Everyday uses

• Deadlines and countdowns. How many days until a launch, an exam, a wedding, or a vacation?
• Project planning. Measure the duration of a sprint, a phase, or an entire project.
• Billing periods. Work out how many days a subscription, lease, or trial actually covers.
• Anniversaries and milestones. Count the days you’ve been at a job, in a relationship, or since any memorable date.
• Age and intervals. Find the exact number of days between two birthdays or historical events.

Key takeaways

• The days between two dates is the later date minus the earlier date.
• Exclusive counting gives the gap; inclusive counting adds one to include both endpoints.
• Divide by 7 to express a day count as weeks and leftover days.
• Date Math shows the total, the weeks breakdown, and an optional business-day count — ready to copy as a sentence.