How to use this date difference calculator
- Enter your start date
- Enter your end date (defaults to today)
- Click Calculate Difference to see the result in days, weeks, months, and more
Common uses for date difference calculators
- Age in days: enter your birth date and today to find your exact age in days
- Project timelines: how many working days between start and deadline
- Event countdowns: days until a wedding, holiday, or exam
- Contract periods: how many days between signing and expiry
- Lease terms: verify the length of a rental agreement
Leap years and date calculations
A leap year occurs every 4 years (with some exceptions for century years). Leap years add an extra day — February 29 — to the calendar. This calculator accounts for leap years automatically, giving you a precise day count regardless of whether the date range spans a leap year or not.
Frequently asked questions
How do I calculate the number of days between two dates?
Subtract the earlier date from the later date. This calculator does this automatically — just enter both dates and it calculates the exact difference in days, weeks, months, and years, accounting for leap years and varying month lengths.
Does this calculator include or exclude the end date?
This calculator counts the number of complete days between the two dates, not including the end date itself. For example, from January 1 to January 3 is 2 days.
How many days are in a year?
A regular year has 365 days. A leap year (divisible by 4, with some exceptions) has 366 days. This calculator accounts for leap years automatically.