Date & time calculator
Standalone tool pageDate Difference Calculator
Count days and approximate weeks/months/years between two dates.
Result
Total days
Weeks
Months*
Years*
*Months and years are approximate using average lengths.
How It Works
The calculator compares two calendar dates at midnight and returns the absolute difference in days. It then converts the same day count into approximate weeks, months, and years for quick planning context.
Example
From January 1 to January 31 is 30 days between dates. The week, month, and year summaries are helpful approximations, but exact calendar months can vary from 28 to 31 days.
Planning examples
- Count days until a deadline or event.
- Estimate weeks between two project milestones.
- Check rough months or years between dates.
- Compare with the add-days calculator when you need a future or past target date.
Calendar assumptions
- Total days are the most reliable output.
- Weeks are calculated from total days divided by 7.
- Months and years are approximate because calendar lengths vary.
- Public holidays and business-day rules are handled by separate tools.
Frequently Asked Questions
Does it include the end date?
This version counts the difference between dates. Inclusive counting can be added as an option later.
Are months exact?
Months vary in length, so the month and year outputs are approximate summaries based on average lengths.
Does timezone affect the result?
The tool uses date inputs at local midnight. For travel, legal, payroll, or timezone-sensitive planning, verify with an official calendar.
What if the dates are reversed?
The calculator returns the absolute difference, so start and end can be entered in either order.