How do I calculate days between two dates?
Select 'Days Between Dates' mode, enter your start and end dates, then click Calculate. The tool instantly shows total days, weeks, months, working days, and a visual time breakdown.
Date Duration & Day Counter: Accurate Add or Subtract Tool
Calculate date differences, add or subtract days/months/years, and find days between dates instantly. Shows day of week, handles leap years automatically, and supports project planning and deadline tracking.
Others Calculators
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How to Use This Date Calculator
- Select a mode: Add/Subtract Date to find a future or past date, Days Between Dates for the difference, or Days Since to calculate elapsed time from a historical date.
- Enter your start date (and end date for Days Between). For Days Since, enter any past date.
- Optionally enable Exclude Weekends to calculate only business working days.
- Select your country and enable holiday exclusion (USA, UK, India, Canada, Australia, EU).
- Click Calculate to see total days, working days, ISO week, fiscal quarter, year progress, and a time composition chart.
US Business Working Days by Month — 2026
Exact working days per month for 2026, accounting for all 11 US federal holidays. Essential for payroll planning, project timelines, and HR scheduling.
| Month | Calendar Days | Weekdays | Holidays | Net Working Days |
|---|---|---|---|---|
| January 2026 | 31 | 22 | 1 | 21 |
| February 2026 | 28 | 20 | — | 20 |
| March 2026 | 31 | 22 | — | 22 |
| April 2026 | 30 | 22 | — | 22 |
| May 2026 | 31 | 20 | 1 | 19 |
| June 2026 | 30 | 22 | 1 | 21 |
| July 2026 | 31 | 23 | 1 | 22 |
| August 2026 | 31 | 21 | — | 21 |
| September 2026 | 30 | 22 | 1 | 21 |
| October 2026 | 31 | 22 | 1 | 21 |
| November 2026 | 30 | 19 | 2 | 17 |
| December 2026 | 31 | 23 | 1 | 22 |
| Total 2026 | 365 | 261 | 11 | 250 |
Based on 11 US federal holidays. "Net Working Days" excludes both weekends and federal holidays. Actual working days may vary by state, employer, and observed holiday rules.
US Business Working Days by Month — 2027
Planning ahead for 2027? Here are the exact business days per month with US federal holidays factored in.
| Month | Calendar Days | Weekdays | Holidays | Net Working Days |
|---|---|---|---|---|
| January 2027 | 31 | 21 | 2 | 19 |
| February 2027 | 28 | 20 | 1 | 19 |
| March 2027 | 31 | 23 | — | 23 |
| April 2027 | 30 | 22 | — | 22 |
| May 2027 | 31 | 20 | 1 | 19 |
| June 2027 | 30 | 22 | 1 | 21 |
| July 2027 | 31 | 22 | 1 | 21 |
| August 2027 | 31 | 22 | — | 22 |
| September 2027 | 30 | 22 | 1 | 21 |
| October 2027 | 31 | 21 | 1 | 20 |
| November 2027 | 30 | 21 | 2 | 19 |
| December 2027 | 31 | 23 | 1 | 22 |
| Total 2027 | 365 | 261 | 13 | 248 |
Note: When a holiday falls on Saturday, it is typically observed on Friday. When it falls on Sunday, it is observed on Monday.
HR & Payroll Professional Date Calculations
Human resources professionals rely on precise date arithmetic daily. The following calculations demonstrate how to use the date calculator for common HR scenarios.
Notice Period End Date
To calculate a resignation notice period end date: enter the resignation date as your start date, select Add, and add the notice period days (typically 30, 60, or 90 days for US roles, or 10–12 weeks for UK senior positions). Enable Exclude Weekends if your employment contract specifies working days rather than calendar days.
Probation Period End Date
Most US employers use 30, 60, or 90-day probationary periods. Add the probation duration to the employee's start date using the Add/Subtract Date mode. Use the +90d preset for standard 90-day probations to instantly calculate the review date.
FMLA Leave Duration
The Family and Medical Leave Act (FMLA) entitles eligible employees to 12 weeks (84 calendar days) of unpaid leave per year. Use Days Between Dates mode with Exclude Weekends disabled to count calendar days accurately, since FMLA uses calendar days, not working days.
Payroll Period Calculation
For bi-weekly payroll: add 14 days to the last pay date to find the next. For semi-monthly payroll (1st and 15th): use Days Between mode to verify there are always 15–16 days between periods. The business days by month table above shows exactly how many payable working days fall in each month.
📌 HR Quick Reference
- Standard US notice period: 2 weeks (10 business days)
- Standard probationary period: 90 calendar days
- FMLA entitlement: 84 calendar days (12 weeks)
- WARN Act notice requirement: 60 calendar days
- I-9 reverification window: 3 business days from start date
Legal & Contract Date Calculations
Legal deadlines are governed by specific rules about how days are counted. Understanding whether a deadline uses calendar days, business days, or court days is critical before relying on any date calculator.
Contract Expiry & Renewal Dates
For a 12-month contract signed on a specific date, add exactly 365 days (or 366 for a leap year period). Note that “one year from today” is not always 365 days — use the +1yr preset in Add/Subtract mode, which correctly handles calendar month-based anniversary dates.
30-Day Notice Periods
Lease terminations, service cancellations, and contractor agreements often require 30 calendar days' written notice. Enter your notice date and add 30 days. The result tells you the earliest effective termination date. Many courts interpret “30 days” as 30 calendar days unless the contract specifies business days.
Filing Deadlines & Response Periods
Court filing deadlines in the US commonly use calendar days. An “answer within 21 days of service” means 21 calendar days from the service date, including weekends. Add 21 days to the service date using Add/Subtract mode with no weekend exclusion. Many jurisdictions add extra days when a deadline falls on a weekend or holiday.
Project Management & Agile Sprint Date Planning
Accurate date arithmetic is foundational to project delivery. Whether you use Agile, Waterfall, or a hybrid methodology, the following patterns show how to use this calculator for professional project planning.
Agile Sprint End Date Calculator
For a standard 2-week sprint: enter the sprint start date and add 14 calendar days (or 10 business days if your team counts only working days). For Q4 2026 sprint planning, reference the business days table above to see exactly how many working days fall in November and December after accounting for Thanksgiving and Christmas.
Project Milestone Date Calculation
For a 90-business-day project starting January 5, 2026: use Days Between Dates mode with Exclude Weekends enabled. Or use Add/Subtract mode and add days manually. Always verify milestone dates fall on weekdays — the calculator shows the day of week automatically.
Sprint Velocity & Quarter Capacity
| Quarter 2026 | Business Days | 2-Week Sprints | 1-Week Sprints |
|---|---|---|---|
| Q1 (Jan–Mar) | 63 | 6.3 | 12.6 |
| Q2 (Apr–Jun) | 64 | 6.4 | 12.8 |
| Q3 (Jul–Sep) | 64 | 6.4 | 12.8 |
| Q4 (Oct–Dec) | 60 | 6.0 | 12.0 |
ISO Week Numbers for Sprint Tracking
Many project management tools (Jira, Azure DevOps) reference ISO week numbers for sprint labelling. The date calculator displays the ISO week number for any result date. ISO Week 1 of 2026 begins on Monday, December 29, 2025. ISO Week 53 of 2025 contains December 29–January 4, 2026.
How Many Days Since? — Reference Examples
Use the Days Since mode to calculate elapsed time from any past date. Values below are calculated as of January 1, 2026.
| Event / Date | Calendar Date | Days Since (Jan 1, 2026) |
|---|---|---|
| Start of Year 2000 | Jan 1, 2000 | 9,497 |
| 9/11 (Sept 11, 2001) | Sep 11, 2001 | 8,877 |
| iPhone first released | Jun 29, 2007 | 6,760 |
| Start of COVID-19 Pandemic | Mar 11, 2020 | 2,122 |
| Start of Year 2020 | Jan 1, 2020 | 2,192 |
| Start of Year 2025 | Jan 1, 2025 | 365 |
| 10 years ago | Jan 1, 2016 | 3,653 |
| 25 years ago | Jan 1, 2001 | 9,131 |
Use the Days Since calculator above to get the exact number of days for any date, updated to today.
History of the Gregorian Calendar
The Gregorian calendar was introduced in 1582 by Pope Gregory XIII to correct inaccuracies in the Julian calendar. The Julian system calculated a year as exactly 365.25 days, but the actual tropical solar year is approximately 365.2425 days — a difference of about 11 minutes per year that accumulated over centuries, causing the calendar to drift from the astronomical spring equinox.
The Gregorian reform introduced a refined leap year rule: a year is a leap year if divisible by 4,except century years (divisible by 100) are only leap years if also divisible by 400. Thus 1900 was not a leap year, but 2000 was. This gives the Gregorian calendar an average year of 365.2425 days — accurate to within one day over approximately 3,300 years.
Today, the Gregorian calendar is the internationally accepted civil standard used in virtually every country, making it the foundation for all date calculations on this tool, including business day counting, ISO week numbering, and holiday scheduling.
Real-World Date Calculator Examples
These practical examples show how to apply the date calculator in everyday and professional contexts:
Shipping & Delivery Timelines
If a package ships on March 1 and the carrier quotes 7 business days, add 7 business days using Days Between mode with Exclude Weekends enabled. The result accounts for any weekends in the delivery window.
Event Countdowns
Planning a product launch for June 15, 2026? Use Days Between Dates from today's date to June 15 to get an exact day count — useful for marketing campaign scheduling and team milestone planning.
Subscription Renewals
Add 365 days (or use +1yr preset) to your subscription start date to find the exact renewal date. For 30-day trials, use +30d preset to instantly calculate expiry.
Employee Milestones
Calculate a 1-year work anniversary using +1yr preset on the hire date. For a 90-day performance review, use +90d. The ISO week number tells you which planning period the milestone falls in.
Academic Deadline Tracking
Enter your course start date and add the number of days to an assignment deadline. Students can use Days Between with today's date to count down exactly how many days remain to complete work.
Understanding Public Holidays in Date Calculations
Public holidays directly affect the number of working days available within any period, making them critical for payroll, legal deadline, and project planning calculations.
Regional Differences
Holiday interpretation varies by country and even by state. Boxing Day is a statutory holiday in Canada and the UK but not recognized federally in the United States. The US has 11 federal holidays; India recognizes 18 national holidays; the UK has 8.
Fixed vs. Floating Holidays
Fixed holidays occur on the same calendar date each year (e.g., Independence Day on July 4). Floating holidays change annually — Thanksgiving falls on the fourth Thursday of November, and Easter is calculated using the Computus algorithm based on lunar cycles.
Observed vs. Actual Dates
When a US federal holiday falls on a Saturday, it is typically observed on the preceding Friday. When it falls on a Sunday, it is observed on the following Monday. The working days tables above account for these observed date adjustments.
2026 U.S. Federal Holidays
| Holiday | Date (2026) |
|---|---|
| New Year's Day | January 1, 2026 |
| Martin Luther King Jr. Day | January 19, 2026 |
| Presidents' Day | February 16, 2026 |
| Memorial Day | May 25, 2026 |
| Juneteenth | June 19, 2026 |
| Independence Day | July 4, 2026 |
| Labor Day | September 7, 2026 |
| Columbus Day | October 12, 2026 |
| Veterans Day | November 11, 2026 |
| Thanksgiving | November 26, 2026 |
| Christmas Day | December 25, 2026 |
* July 4 falls on Saturday in 2026. Many federal offices observe Friday July 3 as the holiday.
2027 U.S. Federal Holidays
| Holiday | Date (2027) |
|---|---|
| New Year's Day | January 1, 2027 |
| Martin Luther King Jr. Day | January 18, 2027 |
| Presidents' Day | February 15, 2027 |
| Memorial Day | May 31, 2027 |
| Juneteenth | June 19, 2027 |
| Independence Day | July 4, 2027 |
| Labor Day | September 6, 2027 |
| Columbus Day | October 11, 2027 |
| Veterans Day | November 11, 2027 |
| Thanksgiving | November 25, 2027 |
| Christmas Day | December 25, 2027 |
* Saturday holidays observed on Friday. ** Sunday holidays observed on Monday.
Who Uses a Date Calculator?
Students & Academic Use
Track assignment deadlines, plan exam study schedules, and calculate academic year timelines. A student can use Days Since to see how many days into a semester they are, or add days to today to find an essay due date.
HR & Payroll Professionals
Calculate notice periods, probation end dates, FMLA eligibility windows, payroll period boundaries, and employee anniversaries. The business days tables above are particularly useful for headcount planning.
Project Managers & Agile Teams
Calculate sprint end dates, project milestones, and delivery deadlines. Use the ISO week number feature to align results with project management software sprint labels.
Legal & Compliance Teams
Verify contract expiry dates, calculate statutory response periods, and ensure filing deadlines are met. Always cross-reference with applicable court rules.
Personal Planning
Count down to weddings, birthdays, travel, and personal milestones. Use Days Since to calculate ages in days or see how long a relationship, job, or life chapter has lasted.
Date Difference Calculator vs. Days Counter — What's the Difference?
Both tools work with dates, but they answer different questions:
| Feature | Date Difference Calculator | Days Counter |
|---|---|---|
| Question Answered | How long is the period between two dates? | What date is X days from now? |
| Input Required | Two dates (start + end) | One date + number of days |
| Output Format | Days, weeks, months, exact breakdown | A specific future or past date |
| Best For | Project duration, age, contract periods | Finding deadlines, expiry dates |
| Business Days | Yes — with weekend and holiday exclusion | Yes — add only working days |
This tool combines all three modes — date difference, days counter, and days since — in a single interface.
Frequently Asked Questions
How do I calculate business days between two dates?
In 'Days Between Dates' mode, enable 'Exclude Weekends' to count only Monday through Friday. Then select your country and enable holiday exclusion to subtract public holidays from the working day count.
How do I calculate a notice period end date?
Use 'Add/Subtract Date' mode. Enter your resignation or notice start date, select Add, and add your required notice period days (e.g., 30, 60, or 90). The result shows the exact last working day.
Can I calculate a project sprint end date?
Yes. Use Add/Subtract mode with your sprint start date, then add the sprint duration (14 days for 2-week sprints, 10 for 2-week working-day sprints). The result shows the day of week and ISO week number.
Does the date calculator account for leap years?
Yes. Leap year logic is built in. February 29 is correctly handled in all modes — adding 1 year to Feb 29 in a leap year gives Feb 28 in the following non-leap year.
How do I find how many days since a past date?
Select 'Days Since' mode, enter the historical date, and click Calculate. The result shows total days elapsed, plus an exact breakdown of years, months, and days.
How are working days calculated?
Working days count only Monday through Friday. The calculator iterates through each day in the range and skips Saturdays and Sundays. With holiday exclusion enabled, country-specific public holidays are also subtracted.
How many business days are in 2026?
There are 250 net business working days in 2026 for the United States, after excluding 11 federal holidays and all weekends from the 261 total weekdays in the year.
Can I export or share my date calculation?
Yes. Results can be shared via a unique URL, downloaded as a .txt report, exported as a .ics calendar file for any calendar app, or added directly to Google Calendar.
What is an ISO week number?
ISO week numbers (ISO 8601) divide the year into 52 or 53 weeks, where Week 1 is the week containing the year's first Thursday. Week numbers are widely used in project management, logistics, and financial reporting.
What is the difference between calendar days and business days?
Calendar days count every day of the week including weekends and holidays. Business days count only Monday through Friday, and may further exclude public holidays. Legal contracts specify which type of day is intended.
How do I calculate an FMLA leave end date?
FMLA entitles eligible employees to 12 weeks (84 calendar days) of unpaid leave. Use Add/Subtract mode, enter the leave start date, and add 84 days without excluding weekends, since FMLA uses calendar days not business days.
Expert Review & Verification
This Date Calculator is independently developed and maintained by Raviraj Bhosale. All calculation algorithms are reviewed against internationally recognized calendar standards.
Gregorian Calendar Standard: Calculations follow the internationally recognized Gregorian calendar, including correct leap year handling. timeanddate.com (Gregorian)
Leap Year Definition: February 29 handling follows the standard rule: divisible by 4, except centuries must be divisible by 400. timeanddate.com (Leap Years)
Business Day Convention: Weekend exclusion follows the standard Mon–Fri business day definition used in financial and legal contexts. timeanddate.com (Workdays)
ISO 8601 Date Standard: Date difference calculations and week numbers follow ISO 8601, the international standard for dates and times. ISO 8601 Standard
US Federal Holiday Dates: Federal holiday dates are sourced from the US Office of Personnel Management official schedule. OPM Federal Holidays
Privacy & Transparency: All date calculations are processed locally in your browser. No date data is stored, transmitted, or shared with any third party.
Last reviewed: January 2026. For legal, financial, or contractual deadlines, always consult qualified professionals.
Expertise & Trust (Human Verified)
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