Date Difference Calculator
The exact time between two dates.
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Enter two dates and see exactly how far apart they are — in years, months, and days, and also as total days, weeks, hours, and average months. Correct across leap years, so durations spanning a 29 February come out right.
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How Many Days Between Two Dates? — The Quick Answer
Subtract the earlier date from the later one and count the calendar days in between. The precise answer is best expressed as years, months, and days together, because months have different lengths.
Shortcut
difference = later date − earlier date (counted in real calendar days)
How the same span looks in different units
| Unit | Meaning |
|---|---|
| Days | exact calendar days between the dates |
| Weeks | days ÷ 7 |
| Months (avg) | days ÷ 30.44 |
| Years (avg) | days ÷ 365.25 |
The years-months-days breakdown is the most precise, because it respects the real length of each month. The 'average months' and 'average years' figures use averaged lengths, so they're useful estimates rather than exact counts.
How It Works
The Method
Real calendar counting
Formula
total days = later date − earlier date breakdown = whole years + months + leftover days
Variables
The precise breakdown
Counts whole years first, then whole months, then the remaining days — so '1 year, 2 months, 5 days' is exact, unlike dividing total days by 365.
Average years
Dividing total days by 365.25 (a year's average length including leap years) gives a decimal year count — convenient for comparisons, but slightly less precise than the y/m/d breakdown.
Note: This counts calendar days, including weekends. For working-day counts that skip weekends, use the Business Days Calculator.
Last updated: October 5, 2026
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Frequently Asked Questions
How do I calculate the number of days between two dates?
Enter both dates. The calculator counts the real calendar days between them — for example from 1 January 2020 to 15 March 2024 is exactly 1,535 days. It also expresses the same span as years, months, and days: 4 years, 2 months, 14 days.
Why show years, months, and days instead of just days?
Because months have 28–31 days, a single 'days' number is exact but hard to interpret. Breaking the span into whole years, whole months, and leftover days gives the answer people actually want — 'you've been here 3 years and 4 months' — while staying precise.
Does it count the start and end dates?
It counts the number of days between the dates — the interval. Using this calculator on the same two dates, 1 January to 2 January is 1 day apart. This matches how 'days until' a date is usually counted.
Does it account for leap years?
Yes. The calculator counts actual calendar days, so a 29 February inside your range contributes its extra day and the totals stay correct — unlike rough '× 365' maths which drifts over multi-year spans.