Date Calculator
Calculate the number of days, weeks, and calendar differences between two dates. You can also add or subtract dates and run a countdown.
Total difference365 days
Years / months / days1y 0m 0d
Weeks / days52w 1d
Start weekdaySat
End weekdaySun
How to Use the Date Calculator
- Date difference: Compare two dates and see total days, weeks, and calendar difference.
- Add or subtract: Add years, months, or days to a base date.
- Countdown: Track days remaining until a target date, or days since it passed.
Examples
Example: January 1, 2025 to December 31, 2025
- Total days: 364 days
- Weeks: 52 weeks 0 days
- Calendar difference: 0 years 11 months 30 days
Example: 100 days from today
In add/subtract mode, enter 100 in the days field to see the resulting date and weekday.
Frequently Asked Questions
Can I calculate only business days?
Not yet. This calculator shows total calendar days, so you need to subtract weekends and holidays separately.
How can I estimate a due date?
Set the start date to the first day of the last menstrual period and add 280 days in add/subtract mode.
How do I calculate 100-day or 200-day anniversaries?
Use add/subtract mode and add 99 days to the start date if you count the start day as day 1.