Date Difference Calculator

Calculate the exact time between any two dates in days, weeks, months, years, and business days.

Difference

—

Years, months, and days

Total Days

—

Calendar days between dates

Total Weeks

—

Complete weeks and remaining days

Business Days

—

Weekdays only (Mon-Fri)

Date Math Guide

Business Day Calculations

Business days (also called working days) exclude weekends. They are commonly used for shipping estimates, project deadlines, legal deadlines, and financial settlement dates. Most industries consider Monday through Friday as business days.

  • Shipping: "5 business days" means 5 weekdays, which could be 7 calendar days.
  • Legal deadlines: Court filing deadlines often use business days, excluding weekends and court holidays.
  • Financial: Stock market settlement (T+2) counts business days only.

Common Date Ranges

Period Days
1 week 7 days (5 business)
1 month 28-31 days (~22 business)
1 quarter 90-92 days (~65 business)
1 year 365-366 days (~261 business)

Tips for Date Math

  • When a deadline says "within 30 days," clarify whether that means calendar days or business days.
  • International date formats vary: US uses MM/DD/YYYY while most other countries use DD/MM/YYYY.
  • Time zones can affect date calculations when working across regions.

Note: Business day calculations exclude weekends but do not account for public holidays, which vary by country and region.

Frequently Asked Questions

How are business days calculated?
Business days count only weekdays (Monday through Friday), excluding Saturdays and Sundays. This calculator does not account for public holidays, as these vary by country and region. For precise business day calculations involving holidays, you would need to factor in the specific holiday calendar for your location.
Does this calculator account for leap years?
Yes. The calculator uses JavaScript Date objects, which correctly handle leap years and varying month lengths. Whether your date range spans a leap year February or not, the day count will be accurate. A leap year adds one extra day (February 29), which is included in the total.
Can I calculate dates in the past?
Yes, the calculator works with any two dates regardless of whether they are in the past, present, or future. If the end date is before the start date, the calculator will still show the absolute difference between the two dates. This is useful for historical calculations or planning.
Why does the month count differ from what I expect?
Months have different lengths (28 to 31 days), so the calculator counts complete calendar months by comparing day values. For example, January 31 to February 28 counts as 0 complete months and 28 days, not 1 month, because February does not have a 31st. The total days count is always exact regardless of month length differences.

Related Calculators

🎂
Everyday

Age Calculator

Calculate exact age in years, months, and days from any birth date.

⛽
Everyday

Fuel Cost Calculator

Estimate fuel costs for any trip based on distance, fuel efficiency, and gas prices.

🖥️
Everyday

Screen Size Calculator

Calculate screen dimensions, aspect ratio, and PPI from diagonal screen size.

🔒
Everyday

Password Strength Checker

Check how strong your password is and get suggestions to improve it.

🌍
Everyday

Time Zone Converter

Convert time between any world time zones with automatic daylight saving adjustments.

💰
Finance

Loan Calculator

Calculate monthly payments, total interest, and amortization schedule for any loan type.