Days Between Dates Calculator
Find out exactly how many days, weeks, or business days fall between any two dates.
Your date breakdown will appear here
Enter a start date and an end date, then click calculate to see the breakdown.
Quick Answer
This calculator finds the number of days between two dates by counting every calendar day from the start date to the end date, accounting for leap years.
How It Works: Formula & Variables
Days Between = End Date − Start Date (in days)
- Start Date
- The earlier date in the range you want to measure.
- End Date
- The later date in the range — defaults to today, but can be any past or future date.
Business-day mode excludes Saturdays and Sundays from the count.
Worked Examples
Example 1: Half-year span
From January 1, 2026 to June 21, 2026 is 171 days.
Example 2: Spanning a year boundary
From December 15, 2025 to March 1, 2026 is 76 days.
Key Concepts
Inclusive vs. exclusive counting: Deciding whether to count the start or end day changes the total by one day, so be clear about which convention you're using.
Business days exclude weekends: Business-day counts skip Saturdays and Sundays, and sometimes public holidays, depending on the context.
Year boundaries don't reset the day count: Counting across December 31 into January 1 continues the day count uninterrupted — the calendar year doesn't restart the tally.
Common Mistakes
Forgetting whether to count the start/end date itself: Mixing up inclusive and exclusive counting is the most common source of off-by-one errors.
Manually miscounting days in February during leap years: Forgetting the extra day in a leap year throws off manual calculations by a day.
Confusing calendar days with business days: A "30 day" deadline can mean very different end dates depending on whether weekends are included.
Frequently Asked Questions
This calculator counts the number of days between the two dates (the difference), not an inclusive count of both endpoints — if you need both dates included, add 1 to the result.
Turn on the 'exclude weekends' option to count only Monday through Friday in the date range. Note this doesn't automatically exclude public holidays.
Set the start date to today and the end date to the future date you're counting toward — the result is the number of days remaining.
Yes — the calculation is based on actual calendar dates, so leap years (with their extra day in February) are automatically handled correctly.