Free Days Between Dates Calculator Online
Need to count the exact number of days between dates? This free online days between dates calculator returns the total in days, weeks, months, workdays, hours, and minutes. Enter any start and end date — past or future — and get a visual breakdown instantly. No sign-up needed.
Days Between Dates
Workdays vs Weekend Days
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Years
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Months
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Weeks
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Days
How to Count Days Between Dates
Every date can be expressed as a timestamp — the number of milliseconds since January 1, 1970. To find the days between dates, the calculator subtracts the start date's timestamp from the end date's timestamp, then divides by 86,400,000 (the number of milliseconds in a day). The result is rounded to the nearest whole number to eliminate any floating-point noise. That's it — no loops, no month-by-month iteration.
Mental counting fails surprisingly quickly across year boundaries. If you try to count days between dates like November 15 and February 20 in your head, you have to remember that November has 30 days, December has 31, January has 31, and February's length depends on whether the year is a leap year. Most people give up and estimate — which is fine for casual purposes but dangerous for legal notices, loan terms, or project deadlines. A calculator handles all the edge cases automatically.
There's also the inclusive vs. exclusive question: does "April 1 to April 5" equal 4 days or 5? Convention varies by context. Courts often use inclusive counting for notice periods, while project managers typically count elapsed days (exclusive). This days between dates calculator uses exclusive counting — the same approach as most spreadsheet date functions — so you get 4 for that example. If you need the inclusive count, just add 1 to the displayed result.
Common Uses for This Calculator
Project Deadlines
See the exact days remaining before a project or contract end date. Knowing the precise count helps with sprint planning and milestone scheduling.
Legal Notice Periods
Rental notices, contract terminations, and legal filings often require exactly 30 or 60 days between dates. A miscalculation here can void the notice entirely.
Personal Milestones
Count the days until a wedding, graduation, or anniversary — or look back at how many days have passed since a meaningful date.
Age at a Past Event
Find how old you were (or will be) at a specific date by using your birthdate as the start date and the event date as the end.
Workdays vs Calendar Days
When you calculate days between dates for a business purpose, calendar days and workdays are two very different numbers. Calendar days count every single day in the span — weekends included. Workdays strip out Saturdays and Sundays, giving you the number of days you could realistically spend working.
The simplified formula used here is: Math.floor(totalDays / 7) * 5 + Math.min(5, totalDays % 7). Full weeks each contribute exactly 5 workdays. The leftover days contribute however many they are, capped at 5 (so a 6-day remainder doesn't accidentally count both weekend days as workdays). This estimate is accurate when the span doesn't start on a weekend day, but it doesn't account for public holidays — those vary by country and industry.
Real example: April 1 to May 1, 2026 is 30 calendar days and approximately 22 workdays. The 8-day gap represents the four weekends within that month.
Leap Years and Counting Accuracy
A leap year adds one extra day — February 29 — every four years, with the exception of century years not divisible by 400. This means a standard year has 365 days while a leap year has 366. When you calculate days between dates that span a February 29, the result will be one day larger than you'd get by naively multiplying years by 365.
This calculator handles leap years automatically because it works in milliseconds rather than counting days by calendar rules. For example: February 1, 2024 to February 1, 2025 = 366 days, because 2024 is a leap year and February 29, 2024 falls within that span. February 1, 2023 to February 1, 2024 = 365 days, because no leap day occurs. The timestamp approach means you never need to mentally check whether a leap day is included.
Did You Know?
86,400
Seconds in a single day. Multiply your days between dates by this number to get the total seconds elapsed across that span.
365.2425
Average days per year in the Gregorian calendar across a 400-year cycle — the reason we add a leap day every 4 years (with exceptions for century years).
1582
Year the Gregorian calendar replaced the Julian calendar. Ten days were simply skipped in October that year — which would really break any days between dates calculator.
Frequently Asked Questions
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