Days Between Dates Calculator

Use this days between dates calculator to find the exact duration between any two dates. Enter your start date, end date, and choose exclusion options.

Updated: May 21, 2026 • Free Tool

Days Between Dates

Select the beginning date of the period.

Select the ending date of the period.

Check this if you want to count both the start date and the end date as full days.

Check this if you want to calculate only working days (Monday through Friday).

Results

Total Days
1
Calendar Breakdown 1 day
Weeks Breakdown 0 weeks, 1 day

What is a Days Between Dates Calculator?

A days between dates calculator is a simple yet powerful online tool designed to help you quickly determine the exact duration between any two calendar dates. Instead of manually turning physical calendar pages or attempting mental calculations that easily lead to errors, this tool lets you find the exact gap in days instantly.

This utility is incredibly helpful for several scenarios:

  • Project Management: Plan task durations and tracking deadlines.
  • Event Planning: Countdown the days remaining until a wedding, vacation, or anniversary.
  • Age & Milestone Tracking: Calculating your age in days or finding days since a significant historical event.
  • Billing & Contracts: Verifying interest periods or contract lengths.

To calculate complete calendar spans including hours, explore our Time Between Dates Calculator to analyze time gaps.

How the Days Between Dates Calculator Works

The calculation finds the absolute difference in milliseconds between the start date and the end date. This milliseconds difference is then divided by 86,400,000 (the number of milliseconds in a day: 1000 ms * 60 s * 60 m * 24 h). To ensure timezone safety, all dates are processed in Coordinated Universal Time (UTC).

Days = (End Date - Start Date) / 86,400,000

According to ExcelJet, the DAYS function returns the number of days between two dates by subtracting the start date from the end date.

To perform add or subtract calculations on calendar days, check out our Date to Date Calculator to manage dates.

Key Concepts & Terminology

Calendar Days

Every day on the calendar is counted, including weekends and holidays.

Inclusive Counting

Counting both the start and end dates in the total duration (adding one day to the result).

Working Days

Excluding Saturdays and Sundays to calculate business or school day durations.

Time Zone Shift

Adjusting for local daylight saving transitions that might alter day lengths.

To see a live countdown timer to a specific calendar event, use our Date Countdown Calculator to track events.

How to Use This Days Between Dates Calculator

1

Select Start Date

Select your start date using the calendar input field.

2

Select End Date

Choose your end date in the second date field.

3

Toggle End Date

Toggle whether you want to include the end date in your calculation.

4

Exclude Weekends

Enable the exclude weekends option if you only want to measure working days.

5

Review Output

Review the calculated total days alongside the equivalent months, weeks, and hours breakdowns.

To discover your exact lifetime age measured in calendar days, check out our Age In Days Calculator to calculate your age.

Benefits of Using This Online Calculator

  • Time Savings: Instantly calculate date intervals without manual calendar counting.
  • Absolute Accuracy: Automatically accounts for leap years and months with differing numbers of days.
  • Business Utility: Calculate working days for payroll, lead times, and scheduling.
  • Comprehensive Output: Provides detailed breakdowns in weeks, months, and hours.

To calculate exact chronological age from a birth date, try our Chronological Age Calculator to find exact age details.

Key Factors in Date Calculation

Leap Years

The extra day (February 29) added every four years must be correctly accounted for in calculations.

Time Zones

Crossing time zones can shift the exact day transition, requiring standardization to UTC.

Inclusion of End Date

Deciding whether the end date itself represents a complete day of duration.

According to ExcelJet, the NETWORKDAYS function calculates the number of whole working days between a start date and an end date, excluding weekends (Saturdays and Sundays) and optionally holidays.

To convert standard times into decimal formats or hours, check out our Decimal Time Conversion Calculator to process conversions.

Days Between Dates Calculator - Calculate elapsed days and weeks between two dates
Dashboard preview for the Days Between Dates Calculator, featuring customizable start and end dates with exclusion settings.

Frequently Asked Questions (FAQ)

Q: How do I calculate the number of days between two dates?

A: To calculate the number of days between two dates, convert both dates into standard UTC time, calculate the difference in milliseconds, and divide that number by 86,400,000. You can also use online calculators or spreadsheet formulas to instantly obtain the result.

Q: How to calculate days between dates in Excel?

A: In Excel, you can calculate the days between dates by subtracting the start date cell from the end date cell (e.g., =B2-A2). Alternatively, use the DAYS function by typing =DAYS(end_date, start_date) to return the exact count of days.

Q: Does days between dates include the end date?

A: Standard date calculations are exclusive of the end date. However, for many business contracts, travel plans, and booking policies, you should enable inclusive counting, which adds 1 day to the final difference to count both boundary dates.

Q: How to calculate days between two dates in Google Sheets?

A: In Google Sheets, simply use the subtraction formula like =B2-A2, or apply the DAYS function: =DAYS(B2, A2). For counting only business days, use the NETWORKDAYS function, which automatically excludes Saturdays and Sundays from the result.

Q: How do you calculate days between dates manually?

A: To calculate days between dates manually, count the remaining days in the start month, add the standard days of all full intervening months, add the days in the final month, and adjust the total sum for any leap years occurred.

Q: How to find the number of days between two dates in JavaScript?

A: In JavaScript, parse your dates as Date objects, subtract the start date from the end date to get the difference in milliseconds, and divide the result by (1000 * 60 * 60 * 24). Round the final number to the nearest integer using Math.round().