How to Calculate Days Between Dates
To find the number of days between two dates, subtract the earlier date from the later date. Our calculator also shows weeks, months, years, business days, and weekends separately.
Business Days vs Calendar Days
Calendar days include weekends and public holidays. Business days count only Monday to Friday. For contracts, deadlines, and delivery estimates, business days are usually more relevant.
Common Date Calculations
- How many days until Christmas / New Year
- Days between start and end of a project
- Age in days (see our Age Calculator)
- Contract deadline calculations
- How many days until a birthday or event
FAQs
How do I count business days between two dates?
Business days exclude Saturdays and Sundays (and optionally public holidays). To count manually, subtract weekends from total calendar days. Our calculator does this automatically.
How many days are in a year?
A standard year has 365 days. A leap year has 366 days. A leap year occurs every 4 years, except for years divisible by 100 (unless also divisible by 400).
How do I add 30 business days to a date?
Adding business days is more complex than calendar days because you must skip weekends. Use the "Add/Subtract Days" tab above — note it currently adds calendar days. For business days specifically, multiply by 1.4 to estimate the calendar date.