Date Calculator
Pick two dates and instantly get the difference in days, weeks, and hours, in any order.
About This Tool
Date intervals come in handy in many situations: how many days until the next holiday, how many days since a wedding or dating anniversary, a project timeline from kickoff to delivery, how long until a rental contract expires — all of these can be derived quickly from the difference between two dates.
This tool calculates the whole-day difference between two dates and also provides the corresponding weeks (weeks + remainder days), months (approximated by calendar months), and hours, ready to use in different scenarios. The order of the two dates doesn't matter — the tool automatically computes the absolute interval.
The calculation is based on calendar dates (no hours, minutes, or seconds) and uses natural days in your local time zone; year boundaries and leap years (such as February 29) are handled automatically and correctly.
How to Use
- Click a date input and choose the start date from the calendar popup.
- Choose the end date the same way (order doesn't matter).
- Click "Calculate Interval" to see the difference in days, weeks, months, and hours.
Frequently Asked Questions
If both dates are the same day, is the result 0 days?
Yes. When the start and end dates are the same day, the interval is 0 days; for a countdown "up to today", for example, today to tomorrow is 1 day.
Does the day count include both the first and last day?
This tool uses an "elapsed full days" algorithm, i.e., the end date minus the start date. If your use case requires "counting both ends" (for example, a 3-day leave that includes the current day), simply add 1 to the result.
Are calculations accurate across leap years?
Yes. The tool calculates based on real calendar timestamps; the extra February 29 in a leap year is automatically included, with no manual adjustment needed.
How are the months calculated?
Months are approximated by calendar months: first the whole-year difference, then the month and day differences. Since months vary in length, the result may differ slightly from "days ÷ 30" — this is normal.
Can it calculate business days (excluding weekends)?
This tool does not currently offer business-day statistics that exclude weekends. You can estimate business days as roughly 5/7 of the total days, then adjust for actual holidays.