Day Counter — Free Online Day Counting Tool

How to Use the Day Counter

1. Select a start date: Use the start date picker to choose when your counting period begins. The default is today, but you can select any date. Click the calendar icon or type the date directly in YYYY-MM-DD format. You can navigate backward and forward through months and years using the calendar controls.
2. Select an end date: Choose the date where your counting period ends. The default is set 90 days from today to give you a meaningful result immediately. The calculator computes the absolute difference between dates, so it does not matter which date is earlier.
3. Toggle weekend exclusion (optional): If you need to know only business days, enable the "Exclude Weekends" toggle switch. The primary large number will switch from total calendar days to business days (Monday through Friday only). The detailed breakdown still shows both counts regardless of the toggle.
4. Review the results: The results panel provides four key numbers: total calendar days, business days, weekend days, and weeks-plus-remaining-days. Below these cards, the duration breakdown shows the same period expressed in years, months, and days for a human-friendly perspective on longer spans.

Results update instantly as you change either date or toggle the weekend exclusion switch. Use this tool for project deadline estimation, billing period calculations, contract duration verification, or any scenario where you need an accurate day count between two dates.

Day Counting Formula

Variables Explained

• Calendar Days: The total number of days in the date range, computed by taking the absolute millisecond difference between the two dates and dividing by 86,400,000 (the number of milliseconds in one day). This includes weekdays and weekends.
• Business Days: The count of weekdays (Monday through Friday) within the date range. Calculated by iterating through each day and excluding Saturdays (day 6) and Sundays (day 0). Does not account for public holidays.
• Weekend Days: The count of Saturdays and Sundays within the date range. Equals calendar days minus business days.
• Weeks: The number of complete 7-day periods within the total calendar days. Calculated by integer division (floor) of total days by 7.
• Remaining Days: The leftover days after extracting complete weeks. Calculated as total days modulo 7. This value is always between 0 and 6.

Step-by-Step Example

Count the days between March 1, 2026 and June 15, 2026:

1. March has 31 days, so March 1 to April 1 = 31 days
2. April 1 to May 1 = 30 days (April has 30 days)
3. May 1 to June 1 = 31 days (May has 31 days)
4. June 1 to June 15 = 14 days
5. Total calendar days: 31 + 30 + 31 + 14 = 106 days
6. Weeks: floor(106 / 7) = 15 weeks, Remaining: 106 mod 7 = 1 day
7. March 1 is a Sunday, June 15 is a Monday
8. 15 complete weeks contain 30 weekend days, plus checking the partial week
9. Business days: approximately 76 days (106 - 30 weekend days)

Practical Examples

Example 1: Michael's Project Deadline

Michael is a project manager who received a client contract on January 15, 2026, with a delivery deadline of April 30, 2026. He needs to know both the total time available and the actual working days for resource allocation:

• Total calendar days: 105
• Business days: 75
• Weekend days: 30
• Weeks breakdown: 15 weeks

With 75 business days available, Michael can plan 5 two-week sprints (50 days of active development) plus 25 days for testing, review, and buffer. He shares the business day count with his team to set realistic sprint goals and milestone dates. For tracking hours worked on the project, the time card calculator helps him log weekly hours.

Example 2: Rachel's Billing Calculation

Rachel is a freelance consultant who bills clients based on business days worked. She was engaged from February 10, 2026, through March 28, 2026. She needs the exact business day count for her invoice:

• Total calendar days: 46
• Business days: 34
• Weekend days: 12
• Duration: 1 month, 16 days

At her daily rate of $750, Rachel's invoice totals 34 business days multiplied by $750 = $25,500. She subtracts 2 days for a client holiday (Presidents' Day was during this period), bringing the billable total to 32 days and $24,000. The day counter gave her the baseline figure that she adjusted for known holidays. For calculating percentages and markups on her invoices, the percentage calculator is a handy companion tool.

Example 3: Kevin's Contract Duration Verification

Kevin signed a 90-day service agreement on November 1, 2025, and needs to confirm when the contract expires and how many business days it spans:

• Start: November 1, 2025
• End (90 calendar days later): January 30, 2026
• Business days within the period: 64
• Weeks: 12 weeks and 6 days

Kevin confirms the contract runs through January 30, 2026. The 64 business days give the service provider their actual working timeline. Kevin notes that the Thanksgiving, Christmas, and New Year holidays fall within this window, which may reduce effective working days further. He uses the date calculator to double-check the exact expiration date.

Day Count Reference Table

Tips and Complete Guide

Choosing Between Calendar and Business Days

The choice between calendar days and business days depends entirely on context. Legal deadlines are typically specified as calendar days unless the statute or contract explicitly states business days. For example, a "30-day notice period" usually means 30 calendar days. Shipping estimates from carriers like FedEx and UPS usually mean business days. Payroll periods are counted in business days for hourly workers. When in doubt, check the specific agreement, regulation, or industry standard that applies to your situation.

Handling Holidays in Day Counts

Our day counter distinguishes between calendar days and business days (excluding weekends), but does not automatically exclude public holidays because these vary by country and jurisdiction. The United States has 11 federal holidays in 2026, which fall on weekdays and would reduce the annual business day count from 261 to approximately 250. To get an accurate count, find the number of holidays that fall on weekdays within your date range and subtract them from the business day count. For project planning, also consider company-specific closures, floating holidays, and reduced-schedule periods around major holidays.

Day Counting in Legal Contexts

Legal day counting follows specific rules that vary by jurisdiction. In United States federal practice, when computing time periods, the day of the triggering event is excluded and the last day of the period is included (Federal Rules of Civil Procedure, Rule 6). If the last day falls on a weekend or legal holiday, the period extends to the next business day. Many states follow similar but not identical rules. Always verify the counting rules for your specific legal jurisdiction and type of proceeding. This calculator provides the mathematical day count — consult a legal professional for the legal interpretation.

International Date Conventions

While this calculator uses the Gregorian calendar (the international civil calendar standard), be aware that some countries and cultures use different calendars for religious, traditional, or official purposes. The Islamic calendar (Hijri), Hebrew calendar, Chinese lunisolar calendar, and Hindu calendar all have different month lengths and year structures. The ISO 8601 standard defines the internationally recognized date format (YYYY-MM-DD) and week numbering system used in business and technology worldwide. Our calculator follows the Gregorian calendar and ISO date conventions.

Common Mistakes to Avoid

• Assuming every month has 30 days: Months range from 28 to 31 days. February has 28 days (29 in leap years), while January, March, May, July, August, October, and December have 31 days. Using an average of 30 days per month creates cumulative errors over longer periods.
• Forgetting about leap years: Leap years add an extra day (February 29) every 4 years, except for century years not divisible by 400. When counting days across February in a leap year, the count is one day more than in a common year. The year 2028 is the next leap year.
• Confusing business days with weekdays: Business days typically mean weekdays (Monday-Friday), but they can also exclude public holidays depending on context. Always clarify whether "business days" in your specific context includes or excludes holidays.
• Inclusive vs. exclusive counting: Some contexts count both the start and end date (inclusive counting), while others exclude one endpoint. Legal deadlines, rental agreements, and medical prescriptions may each use different conventions. Our calculator uses the standard mathematical convention of excluding the end date.
• Time zone crossing: If your start and end dates are in different time zones, the actual duration in hours may differ from the calendar day count. Our calculator works with dates only, not times, so it always gives whole-day counts based on calendar dates.

Frequently Asked Questions