Math & Everyday
Date Calculator
Pick two dates to count the days between them (including business days), or flip the mode to add or subtract days from a date and land on the exact calendar day.
Quick answer: To find days between dates, subtract the earlier date from the later one using real calendar days — leap years included. A 90-day span typically contains about 64 weekdays and 26 weekend days.
Between two dates, counts every calendar day (order doesn't matter), then splits the span into whole weeks and calendar-accurate months, and tallies Mon–Fri weekdays vs. weekend days. Add / subtract moves by calendar days; the weekdays-only row lands on the date reached when Saturdays and Sundays are skipped while counting.
How it works
1. Pick your two dates
Choose a start and end date to measure the span between them. The calculator counts real calendar days, so leap years and different month lengths are handled exactly.
2. Read the breakdown
The total is broken into weeks and days, calendar months and days, and — most useful for deadlines — weekdays versus weekend days, counting Monday through Friday as business days.
3. Or add and subtract instead
Switch modes to add or subtract a number of days from any date. You get the resulting calendar date and weekday, plus the date you'd land on counting weekdays only.
Frequently asked questions
How do you calculate days between two dates?
Subtract the earlier date from the later one in whole calendar days. Calendars make this error-prone by hand — months have 28 to 31 days and leap years add a day — so a calculator that works from real dates is the reliable way.
How are business days counted?
Business days count only Monday through Friday. This calculator excludes Saturdays and Sundays but not public holidays, which vary by country and state — subtract any holidays in your span manually.
Does the count include both the start and end date?
The count is the difference between the dates — so Monday to Friday is 4 days. If you need both endpoints included (common for rentals or medication schedules), add 1 to the result.