Date Difference Calculator
Calculate the difference between two dates in days, weeks, months, years, and business days, with an option to include the end day.
About the Date Difference Calculator
Our free date difference calculator tells you exactly how much time is between two dates. Enter a start and end date and instantly see the difference in total days, weeks, months, years, business days (weekdays), and hours. Toggle "include end day" depending on whether you want the final day counted. The date math handles leap years and month lengths and runs entirely in your browser. Perfect for deadlines, project planning, countdowns, and counting days between events.
Features
- Difference in days, weeks, months, and years
- Business days (weekdays only) count
- Optional include-end-day toggle
- Total hours and a full breakdown
- Handles leap years and month lengths
- 100% private — browser-only date math
How to use this tool
The Date Difference Calculator works right in your browser — no signup, no installation. Follow these steps:
- Pick a start date and an end date.
- Toggle "include end day" if you want the last day counted.
- Read the difference in days, weeks, months, and business days.
- Copy or download the full breakdown.
Frequently asked questions
How many days are between two dates?
Enter both dates and the calculator shows the total days between them, plus weeks, months, years, and business days. By default the end day is not counted; turn on "include end day" to count it.
What counts as a business day?
Business days are weekdays — Monday through Friday. The calculator skips Saturdays and Sundays. It does not account for public holidays, which vary by country.
Does the order of dates matter?
No. If you enter the end date before the start date, the calculator automatically swaps them and shows the absolute difference.
How are month ends handled?
Complete months use calendar anniversaries clamped to the last day of a shorter month. For example, January 31 to March 1 is one month and one day in a non-leap year. Days and hours are calendar totals, with hours calculated as days × 24.
Using the results
Use the Date Difference Calculator to calculate from the values you enter. Check the displayed units, rounding and supported inputs when interpreting the result.