Calculate days between two dates — or add and subtract days from any date
⚡ Quick Presets — Days From Today
Finding the number of days between two dates is a common task for project planning, deadline tracking, contract duration, academic scheduling, and personal event planning. Our free date calculator gives you the exact difference in years, months, weeks, and total days — instantly and without any account required.
To manually calculate days between two dates, you subtract the earlier date from the later date, taking into account the number of days in each month and whether any leap years fall within the range. February has 28 days in a standard year and 29 days in a leap year. Our calculator handles all of this automatically using the standard Gregorian calendar.
Adding days to a date is useful for calculating deadlines, expiry dates, delivery estimates, and event planning. For example, if a contract starts today and runs for 90 days, our calculator will tell you the exact end date — including the correct weekday. Use the "Add or Subtract Days" section above, enter your base date, the number of days, select "Add", and click Calculate.
A leap year contains 366 days instead of the usual 365, with the extra day added as February 29. A year is a leap year if it is divisible by 4 — except for century years, which must also be divisible by 400. So 2000 and 2400 are leap years, but 1900 and 2100 are not. Leap years matter in date calculations because the extra day shifts all subsequent dates by one position. Our calculator accounts for leap years precisely.
To find out how many days until a specific date — such as a birthday, holiday, exam, or event — set today as your Start Date and your target date as the End Date in the Days Between Two Dates calculator above. The result shows you the exact number of days remaining. You can also use our Countdown Timer to track the time in real-time.
To calculate how many days have passed since a historical date — such as the number of days since someone was born, since a contract was signed, or since a significant event — enter the past date as the Start Date and today as the End Date. The calculator will show the total elapsed days, weeks, months, and years since that date.
Date calculators are widely used in professional settings for calculating contract durations, invoice payment due dates, warranty periods, project deadlines, employee probation periods, and regulatory compliance timelines. When calculating business days specifically — excluding weekends and holidays — the total may differ from calendar days. Our general date calculator counts all calendar days.