Compare multiple date ranges side by side.
| Label | Start | End | Days | Delta |
|---|
Track important dates and see countdowns at a glance.
Select Difference to find the gap between two dates, or Add/Subtract to calculate a future or past date from a starting point.
Pick your start and end dates. Use preset buttons for quick selections like "End of Year" or "90 Days."
Toggle Exclude Weekends for business day calculations, or Include End Date for inclusive counting.
View breakdowns in weeks, hours, minutes, and seconds. Use Scenario Analysis to compare ranges, or the Date Planner for countdown tracking.
End Date − Start DateCalendar Days − Weekend DaysDays + 1 (counts both endpoints)Total Days ÷ 7Total Days × 24Year ÷ 4 = 0 AND (Year ÷ 100 ≠ 0 OR Year ÷ 400 = 0)Any day on the Gregorian calendar, including weekends and holidays.
A weekday (Monday through Friday), excluding Saturdays and Sundays.
Counting method that includes both the start and end dates in the total.
A year with 366 days. Occurs every 4 years except century years not divisible by 400.
The internationally accepted civil calendar introduced by Pope Gregory XIII in 1582.
International standard for date/time representation using YYYY-MM-DD format.
Start: March 19, 2026 → End: December 31, 2026
Result: 287 days = 41.0 weeks = 6,888 hours
Start: January 1, 2026 → End: March 31, 2026 (Exclude Weekends)
Result: 63 business days out of 89 calendar days (26 weekend days excluded)
Start: March 19, 2026 + 90 days
Result: Wednesday, June 17, 2026
Calculating the duration between dates seems simple until you encounter the complexities of real-world calendars. Months have different lengths, leap years add extra days, and business contexts require weekend exclusion. This calculator handles all these edge cases automatically.
Project managers use date duration calculators to determine sprint lengths and delivery timelines. HR departments calculate employment duration for benefits eligibility. Legal professionals count contractual deadlines in business days. Even personal planning benefits from knowing exactly how many days until a vacation, wedding, or retirement date.
The distinction between calendar days and business days is critical in professional settings. A "30-day notice period" in a contract typically means 30 calendar days, while "10 business days for processing" means exactly two weeks. This calculator lets you toggle between both counting methods instantly.
Should you count both the start and end date? It depends on context. If you start a medication on Monday and take it through Friday, that is 5 days of medication (inclusive) but only a 4-day span (exclusive). Legal and financial contexts often specify which method applies. Our "Include End Date" toggle lets you handle both scenarios.
Every four years, February gains an extra day. But century years (1900, 2100) skip the leap year unless divisible by 400 (2000, 2400). This calculator fully accounts for these rules. When a leap year falls within your date range, you will see an informational alert noting how many leap years are included.
Enter your start date and end date in the calculator. It instantly shows the total days, weeks, hours, minutes, and seconds between the two dates, along with a year-month-day breakdown.
Yes. Toggle the "Exclude Weekends" option to calculate only business days (Monday through Friday), automatically skipping Saturdays and Sundays.
Switch to Add/Subtract mode to add or subtract any number of days, weeks, months, or years from a starting date. The result date and day of week are shown instantly.
Yes. All calculations account for leap years and varying month lengths in the Gregorian calendar. The calculator alerts you when leap years fall within your date range.
By default, the count excludes the end date (like counting fence posts vs. gaps). Enabling "Include End Date" adds one extra day to count both the start and end dates.
Yes! Use the Scenario Analysis tab to compare multiple date ranges side by side. Set a base range, then add comparison ranges to see the differences in a table and bar chart.
The Date Planner lets you save important upcoming dates and see countdown timers for each. Add events like deadlines, birthdays, or milestones to track how many days remain.