Days Between Dates Calculator
Calculate total calendar days, business workdays, weekend days, and full duration between any two dates.
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How to Use the Days Between Dates Calculator – Date Difference
- 1Select your start date and end date from the pickers.
- 2Check the optional toggle if you wish to include the final end day (+1 day).
- 3Read the total days, business days (Mon–Fri), and weekend days instantly.
- 4Review the detailed calendar breakdown in years, months, and weeks.
Formula & How It Works
Date Difference & Business Day Algorithm
Calendar day difference converts UTC timestamps to whole 24-hour periods (86,400,000 milliseconds). Business days iterate across each calendar day in the range, incrementing only when the day of the week is Monday through Friday.
Worked Examples
Standard Project Sprint
Input: 2026-06-01 to 2026-06-15
Explanation: A two-week sprint spanning 14 calendar days contains 10 working days and 2 full weekends.
Full Calendar Year (Non-Leap)
Input: 2026-01-01 to 2027-01-01
Explanation: A standard non-leap calendar year consists of 365 days, 52 weeks and 1 day.
Summer Vacation Duration
Input: 2026-07-01 to 2026-08-31 (inclusive)
Explanation: July (31 days) + August (31 days) with inclusive end-date equals 62 total days.
Short Work Week Interval
Input: 2026-03-02 (Mon) to 2026-03-06 (Fri)
Explanation: Without the end date toggle, the duration spans 4 24-hour periods (96 hours).
Frequently Asked Questions
How do you count business days between two dates?▼
Business days include only Monday through Friday. Saturdays and Sundays are excluded from the business day tally.
Should I include the end date in my calculation?▼
Include the end date if you want both the starting day and the final day counted as active days (common in hotel bookings and equipment rentals).
How many business days are in a typical year?▼
A standard calendar year contains 260 to 262 business days depending on which day of the week the year begins.
Does this tool account for national public holidays?▼
Public holidays vary by country and municipality, so this tool strictly counts Monday through Friday as standard workdays.
Can I calculate negative date differences?▼
If the end date is earlier than the start date, the calculator automatically computes the absolute chronological distance between them.
Is there any limit on how far apart the dates can be?▼
No, you can calculate differences spanning centuries or millennia.
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