How Many Days Are Between Two Dates? (Exact & Simple)

The number of days between two dates is simply the difference when you count every single day from the start date to the end date. For most purposes, this means subtracting one date from the other.

Use our Date Difference Calculator to get an instant, accurate count between any two dates.

How Date Differences Work

When calculating days between dates, the method depends on whether you include the start date, end date, or both:

• Exclusive: Count only the days in between (most common)
• Inclusive: Count both the start and end dates
• Semi-inclusive: Count one endpoint but not the other

For example, the days between January 1 and January 10 (exclusive) is 9 days. If you include both dates, it's 10 days.

Leap Years and Edge Cases

February has 28 days in normal years and 29 days in leap years. A year is a leap year if:

• It's divisible by 4, AND
• If divisible by 100, it must also be divisible by 400

So 2024 is a leap year, but 2100 will not be.

Common Mistakes

The most frequent errors people make:

• Off-by-one errors: Forgetting whether to include start or end dates
• Ignoring leap years: Assuming February always has 28 days
• Month length confusion: Not all months have 30 or 31 days

Quick Examples

Here are some common date difference scenarios:

• January 1 to December 31 (same year) = 364 days
• March 1 to March 31 = 30 days
• February 1 to March 1 (leap year) = 29 days
• February 1 to March 1 (normal year) = 28 days