How to Calculate Days Between Dates
Counting days between two dates is useful for deadlines, contracts, billing cycles, event planning, and travel. A date calculator handles leap years and month lengths automatically.
Step-by-step
- 1
Choose your start and end dates
Pick the earlier date and the later date you want to measure between.
- 2
Count the total days
Count every calendar day from the start date to the end date (exclusive of the start date).
- 3
Decide if you need business days
If weekends shouldn't count, use a business day calculator that excludes Saturdays and Sundays.
- 4
Add or subtract if needed
To find a future or past date, add or subtract the number of days from your start date.
Calendar days vs. business days
Calendar days include every day on the calendar. Business days usually count only Monday through Friday and exclude weekends, and sometimes holidays, which matters for shipping and payroll timelines.
Accounting for leap years
Accurate day counting must include leap years and the different lengths of months. A calculator does this for you so you don't have to count manually.
Adding and subtracting days
You can also find a future or past date by adding or subtracting days, weeks, months, or years from a start date — useful for due dates, reminders, and return windows.
Frequently Asked Questions
Does the count include the start date?
Usually not. The number of days between two dates typically excludes the start date and includes the end date.
What's the difference between calendar days and business days?
Calendar days include weekends and holidays, while business days count only weekdays and exclude weekends.
Can I calculate a date that is a number of days from today?
Yes. Add or subtract the number of days from today to find the resulting date.