Date Difference Calculator – Days Between Dates & Countdown
Pick a start and end date to see the full span — or a live countdown when the end date is in the future.
Deadlines, trips, and contracts all need a clear answer to “how long between these two days?” This date difference calculator gives years, months, weeks, remaining days, and a total day count — with leap years handled correctly.
When the end date is still ahead, a live countdown ticks down to that day in your local time zone. Same-day spans show zero total days; reverse order still shows the absolute gap with a clear label.
Looking for age from a birth date instead? Use the Age Calculator.
How to use
- Enter a start date and an end date.
- Read years, months, weeks, days, and total calendar days as they update.
- If the end date is after today, a live countdown (days, hours, minutes, seconds) appears.
- Use Reset to clear both dates.
Tips
- Total days is the count of calendar days from start to end (same-day span = 0).
- Years/months/days use calendar arithmetic — month lengths and leap days are included.
- For hotel “nights,” subtract one from an inclusive stay if your check-out day shouldn’t count.
- This tool uses calendar days, not business days.
FAQ
How are days between dates counted?
Total days is the number of whole calendar days from the start date to the end date. January 1 to January 2 is 1 day. The same date twice is 0 days.
Are leap years included?
Yes. February 29 is counted when it falls in the span, and year/month breakdowns use real month lengths.
What if the end date is before the start date?
The calculator still shows the absolute span and labels the direction (end is earlier). Total days is always a non-negative count.
When does the live countdown appear?
When the end date is after today (in your local time zone), a ticking countdown to the start of that end date appears under the main results.
Does the countdown include today?
The countdown targets local midnight at the start of the end date. Hours and minutes update every second until that moment.
Can I use this for project deadlines?
Yes for calendar spans. If you need business days only, skip weekends and holidays separately — this tool does not exclude them.