📅 Date Difference Calculator
Find days, weeks, or months between two dates.
About this tool
Finds the exact gap between two dates — useful for deadlines, countdowns, anniversaries, or just settling an argument about how long ago something happened.
If one of your two dates is always today and the other is a birthdate, the Age Calculator gives a more detailed years/months/days breakdown.
Worked example
From March 1, 2026 to December 25, 2026 is 299 days — useful for counting down to a wedding, deadline, or trip.
How to use it
- Pick a start date and an end date.
- Press Calculate.
- See the difference broken down by days, weeks, months, and years.
Tips
- Works in either direction — pick any two dates and it'll show the gap regardless of order.
- For age specifically from a birthdate to today, the Age Calculator is a faster shortcut.
- Useful for project deadlines: enter today and your due date to see exactly how many days you have left.
FAQ
Can the end date be in the past?
Yes, the calculator works for any two dates in either order.
Does it count the start and end day both?
It calculates the calendar difference between the two dates, not an inclusive day count.
Can I use this for business days only?
No, this counts all calendar days including weekends.
📖 Want the fuller explanation?
See Counting Business Days & Deadlines for the reasoning behind this calculation, with worked examples.