Days Between Dates Calculator
Find the exact number of days, weeks and business days between two dates.
How do you calculate days between two dates?
The number of days between two dates is found by converting both dates to a common time reference and dividing the difference in milliseconds by the number of milliseconds in a day. This calculator handles the conversion automatically, giving you an exact day count regardless of varying month lengths or leap years.
Why does the business day count matter?
Many deadlines — contracts, shipping estimates, payment terms — are measured in business days rather than calendar days. This calculator walks through every day in your selected range and excludes Saturdays and Sundays, giving you a more realistic figure for work-related planning.
Weeks and months explained
The weeks figure is simply the total days divided by seven, shown to one decimal place. The months figure uses an average month length of 30.44 days (365.25 divided by 12), which accounts for leap years and gives a more accurate approximation than assuming every month has 30 days.
Frequently Asked Questions
How many days are between two dates?
Enter a start date and end date above and the calculator instantly returns the exact number of days between them, along with the equivalent in weeks, months, and business days. It works for any range, whether you're counting days until a future event or days since a past one.
How many days until a specific holiday or event?
Set the start date to today and the end date to the holiday or event you're counting down to, such as Christmas, a birthday, or a wedding. The calculator will show the exact number of days remaining, updated instantly as you adjust either date.
Does this calculator include weekends?
The main "Total Days" result includes every calendar day, weekends included. If you only need working days, check the separate "Business Days" figure in the results breakdown, which excludes Saturdays and Sundays automatically.
What counts as a business day in this calculator?
A business day here is any Monday through Friday within your selected date range; Saturdays and Sundays are excluded from the count. Note that public holidays are not automatically excluded, so if your deadline specifically excludes bank or federal holidays, you may need to subtract those manually.
How many weeks are between two dates?
The weeks figure is calculated by dividing the total number of days between your two dates by seven, shown to one decimal place for precision. This is useful for tracking pregnancy timelines, project schedules, or any duration commonly measured in weeks rather than days.
How many days since a past date?
Set the start date to the past date you're measuring from and the end date to today, and the calculator will return the total elapsed days. This works well for tracking milestones like days smoke-free, days since an injury, or days since starting a new habit.
How is the "months" figure calculated between two dates?
Rather than assuming every month is exactly 30 days, this calculator divides your total day count by 30.44 — the average month length once leap years are factored in over a 4-year cycle. That gives a more accurate approximate month count than a flat 30- or 31-day assumption.
What if I enter an end date before the start date?
The calculator will flag that the end date is before the start date and still show you the absolute number of days between them. This is handy for quickly checking how far in the past a date was relative to a chosen reference date.