How do I count the days between two dates?

Subtract the earlier date from the later date in milliseconds, then divide by 86,400,000 (the number of milliseconds in a day). Our calculator does this instantly — just pick your start and end dates.

How many workdays are between two dates?

Workdays (or business days) exclude Saturdays and Sundays. Our calculator counts each calendar day between the two dates and skips weekends. Note: it does not exclude public holidays.

Does the calculator include both the start and end date?

The calculator counts the total number of days from the start date up to (but not including) the end date. This is the standard convention for date-difference calculations.

📅 Date Calculator

Days Between Dates Calculator

Count the exact number of days, weeks, workdays, hours, and minutes between any two dates. Instant results — no account needed.

Select Date Range

Start Date

End Date

Quick select (from today)

Common Uses for a Date Difference Calculator

Project deadlines

Count the workdays remaining until a project milestone or contract deadline.

Age in days

Pick your birthday as the start date and today as the end date to find your age in days, weeks, and hours.

Event countdowns

Days until a vacation, wedding, product launch, or exam.

Billing periods

Count days in a billing cycle or contract term to prorate fees or services.

Pregnancy / due dates

Track weeks and days from a known conception or LMP date to an expected due date.

Historical durations

How many days between two historical events? Great for research and trivia.

How Date Difference Is Calculated

The calculator subtracts the earlier date from the later date in milliseconds, then converts to days by dividing by 86,400,000 (60 seconds × 60 minutes × 24 hours × 1,000 ms). This gives the exact number of full calendar days.

Workday calculation iterates over each day in the range and skips Saturdays (day 6) and Sundays (day 0). Note: it does not automatically exclude public holidays, which vary by country and region.

Calendar breakdown (years, months, days) accounts for varying month lengths and leap years — so the result matches what you'd count manually on a calendar.

Frequently Asked Questions

How do I count the days between two dates?: Subtract the earlier date from the later one in milliseconds, then divide by 86,400,000. Our calculator does this instantly — just pick your dates.
Does the calculator count the start date or end date?: The total days counts from the start date up to (not including) the end date — standard for date-difference calculations. If you want to include both endpoints, add 1 to the result.
How many workdays are between two dates?: Workdays (Mon–Fri) exclude Saturday and Sunday. Our workday count iterates each calendar day and skips weekends. Public holidays are not excluded, as they vary by location.
What if my end date is before my start date?: The calculator shows the absolute (positive) difference either way and notes that the dates were reversed. This lets you calculate backward from a past event.
Why do some months seem to have different day counts?: The years/months/days breakdown accounts for varying month lengths (28–31 days) and leap years. So '1 month' in the calculator reflects real calendar months, not exactly 30 or 31 days.