Date Difference Calculator
Count the number of days, weeks, and months between any two dates — ideal for deadlines, planning, and anniversaries.
Count the number of days, weeks, and months between any two dates — ideal for deadlines, planning, and anniversaries.
To find the days between two dates, the calculator counts the calendar days from the earlier date to the later one, automatically accounting for differing month lengths and leap years. You simply enter a start date and an end date, and it returns the exact number of days, and often the equivalent in weeks, months, and years. This is far more reliable than manual counting, which is easy to get wrong across month and year boundaries.
Yes. The calculator correctly handles leap years, adding the extra day in February whenever a leap year falls within the date range. Leap years occur every four years, with a refinement that century years are only leap years if divisible by 400. Because the tool uses your device's date logic, these rules are applied automatically, so a span crossing one or more leap years is counted accurately.
By convention, a simple date difference counts the number of full days between the two dates, which usually excludes the start date and includes the end date, or vice versa depending on interpretation. For tasks like counting nights of a hotel stay versus days of an event, the appropriate count can differ by one. It is worth checking whether your situation needs an inclusive or exclusive count and adjusting by a day if necessary.
While this tool focuses on the difference between two known dates, related date calculators let you add or subtract a number of days, weeks, or months from a starting date to find a future or past date. This is useful for working out deadlines, anniversaries, or project milestones. Combining the difference and add-subtract tools covers most everyday date arithmetic needs.
Expressing a span in months and days can be ambiguous because months have different lengths. Most calculators count whole months first and then the remaining days, but the result can appear uneven, for example showing 1 month and 30 days near a month boundary. The day count is always exact and unambiguous, so when precision matters, the total number of days is the most dependable figure.