Date Difference Calculator
Enter two dates below to instantly get the exact difference in days, weeks, months, and years.
How the Difference Is Calculated
Days are counted directly between the two calendar dates. Weeks are days ÷ 7, rounded down. Months and years are calculated calendar-aware, counting complete calendar months rather than approximating with an average month length.
Worked example
From January 1, 2024 to December 25, 2024.
359 days = 51 weeks = 11 months = 0 years.
Frequently Asked Questions
How is the difference between two dates calculated?
The exact number of days between the two dates is counted directly. Weeks are that day count divided by 7 and rounded down. Months and years are calculated calendar-aware — counting complete calendar months, not just dividing days by 30.44 — so January 15 to March 15 comes out to exactly 2 months, not an approximation.
Does the order of the two dates matter?
No. The calculator always treats the earlier date as the start and the later date as the end, so you'll get the same result whichever order you enter them in.
Why don't the months and days add up to a round number?
Calendar months have different lengths (28-31 days), so a whole number of months rarely lines up with a whole number of weeks or days at the same time. The days figure is always the exact count; months and years are the calendar-aware breakdown of that same span.
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