Days Between Two Dates Calculator
The Days Between Two Dates calculator finds the exact number of days separating any two calendar dates. Enter a start date and end date to get the answer instantly, with the result also expressed in weeks, months, and years. Useful for calculating project duration, pregnancy weeks, time until an anniversary, or any time span.
How This Works
The calculator subtracts the start date from the end date and divides by the number of milliseconds in a day to produce the days between. The calculation handles leap years, month length variations, and daylight-saving time automatically. For negative results (if end is before start), we show the absolute value.
Days vs Weeks vs Months
The result shows days as the primary unit, with weeks (divide by 7) and years (divide by 365.25 to account for leap years) as secondary units. Months are not shown because the length of a month varies from 28 to 31 days. For an exact month count between two dates, use our Date Calculator.
Common Uses
Common uses include: planning project timelines, calculating age for medical, legal, or administrative forms, counting days until a wedding or event, measuring the duration of a trip, calculating pregnancy weeks, measuring tenure at a job, counting days between contract milestones, and determining elapsed time for warranty or statute-of-limitations calculations.
Frequently Asked Questions
How accurate is this calculator?
The calculator uses standard JavaScript math, which is accurate to approximately 15 significant decimal digits.
Is this calculator free?
Yes, completely free with no signup required.
Does it save my inputs?
Values are kept during your session but are not saved between visits. You can bookmark a URL with specific parameters to return to.
Can I use this on mobile?
Yes, the calculator is fully responsive and works on phones, tablets, and desktop browsers.
Does the result include weekends?
Depends on the calculator. Date calculators show both calendar days (including weekends) and business days (excluding weekends).
How is this different from Google calculator?
This calculator shows the step-by-step formula and provides specialized features (business days, mixed fractions, percent change) that Google calculator does not.
Can I share my calculation?
Copy the URL from the browser bar to share the current calculation state.
Where can I find more calculators?
See our complete list at /calculator.