Count the Days Between Two Dates
This free days between dates calculator tells you exactly how many days fall between any two dates — plus the equivalent in weeks, months, and years. Pick a start date and an end date above, press Calculate, and you get the full breakdown instantly. It handles leap years and month-length differences automatically, so you never have to count on a calendar or risk an off-by-one error.
How to Use the Calculator
- Choose the start date.
- Choose the end date.
- Press Calculate to see the number of days, weeks, months, and years between them.
The order does not matter — the calculator always returns a positive count of days between the two dates.
How Days Are Counted
The tool converts each date to a precise point in time and finds the difference, then divides by the number of milliseconds in a day to get whole days. Because it works from the actual calendar, it automatically accounts for the 28-, 30-, and 31-day months and for leap years, where February has 29 days. That is why a date calculator is far more reliable than counting by hand, especially across several months or years.
Worked Examples
From January 1 to December 31 of the same non-leap year is 364 days. From one birthday to the next is normally 365 days (366 if a February 29 falls in between). From the 1st to the 15th of a month is 14 days. The calculator gives you the exact figure for any pair of dates, including those spanning decades.
Why Count Days Between Dates?
People count days for all sorts of reasons: how long until a wedding, vacation, or deadline; how many days a project, rental, or subscription has run; the length of a hospital stay or a billing period; or simply how many days old something is. Knowing the count in days, weeks, and months makes planning and record-keeping precise. Project managers track durations, landlords and hotels count nights, and event planners count down — all tasks this calculator handles in a click.
Days, Weeks, Months, and Years
The calculator reports the gap in several units because each is useful in a different context. Days are exact; weeks help with schedules and pay periods; months are handy for rough planning even though they vary in length; and years give the big-picture span. Note that months and years are shown as approximate decimal values (based on the average month of about 30.44 days and year of 365.25 days), because calendar months and years are not all the same length. For an exact count, the days figure is always precise.
Counting Down to a Future Date
A common use is counting down to something you are looking forward to. Set today as the start date and your event as the end date, and the calculator shows exactly how many days are left — useful for countdowns to holidays, birthdays, weddings, exams, or product launches. Because it also shows weeks, you can tell at a glance that, say, 100 days is just over 14 weeks. The same approach works in reverse to measure how long ago something happened.
Frequently Asked Questions
How do I calculate the days between two dates?
Pick both dates in the tool above and it returns the exact number of days, plus weeks, months and years. By hand, you subtract the earlier date from the later one, accounting for month lengths and leap years.
Does it count leap years?
Yes — the calculation uses the real calendar, so leap years and varying month lengths are handled automatically.
Is the days between dates calculator free?
Yes — free, browser-based, and no signup needed.