📅 Date Calculator
Calculate the exact difference between two dates in years, months, days, total days, and weeks. Supports leap years, past and future dates, and D-Day countdowns.
Date Difference
-
Total Days
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days
Total Weeks
-
weeks
Total Months
-
months
End Weekday
-
📐 Formula
Days = |End Date - Start Date| ÷ (1000 × 60 × 60 × 24)
Weeks = Days ÷ 7
Months ≈ Days ÷ 30.436875 (average month length)
💡 Examples
Example 1 – Days until an event
- Start Date
- Today (2026-07-16)
- End Date
- 2026-12-25 (Christmas)
- Result
- ~162 days, 23 weeks 1 day
Example 2 – Work experience duration
- Start Date
- 2020-03-01 (Start date)
- End Date
- 2026-07-16 (Today)
- Result
- ~6 years 4 months 15 days
❓ Frequently Asked Questions
Select a start date and end date from the date pickers, then click "Calculate Difference". The result will show the difference in years, months, days, total days, weeks, and the end date's weekday.
Yes, leap years are automatically handled. The calculator uses JavaScript's Date object, which correctly includes February 29 in leap years for precise calculations.
Yes, both past and future dates are fully supported. If the start date is after the end date, the dates are automatically swapped and the absolute difference is calculated.
Click "Set Today as Start" to automatically fill in today's date, then enter your target event date as the end date to see the exact number of days remaining.
The calculator computes differences with millisecond precision using JavaScript's Date object. All edge cases including leap years and months with different lengths are handled automatically.