Deadline Calculator

Calculate project deadlines in business days, exclude weekends and holidays, and track milestones. Perfect for project managers and teams planning deliverables.

Deadline —

How to Use the Deadline Calculator

This business day calculator helps you plan project timelines by calculating deadlines while accounting for weekends and holidays.

  1. Choose your mode: Calculate days forward from a start date, backward from a deadline, or count business days between two dates.
  2. Enter your dates: Select dates from the calendar picker or type them in YYYY-MM-DD format.
  3. Set business days: Enter the number of working days needed for the task or project.
  4. Configure exclusions: Check or uncheck weekends and holidays based on your work schedule.
  5. View milestones: The calculator shows important milestone dates at 25%, 50%, and 75% completion.

Understanding Business Days

A business day (also called a working day or weekday) is any day that is not a weekend or public holiday. Most organizations use Monday through Friday as business days, though this can vary by country and industry.

When planning projects, using business days instead of calendar days gives a more accurate timeline because it accounts for days when your team is not working. For example, if you need to complete a task in 5 business days starting on a Friday, the deadline would be the following Friday, not the following Tuesday.

Why Exclude Holidays?

US federal holidays include New Year's Day, Martin Luther King Jr. Day, Presidents' Day, Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, and Christmas. When these holidays fall on business days, they reduce the number of working days available. This calculator can automatically account for these holidays to give you more accurate project timelines.

Common Project Scenarios

ScenarioStart DateBusiness DaysDeadline
Sprint planning (2 weeks)Monday10 daysFriday (2 weeks later)
Client revision deadlineMonday5 daysMonday (next week)
Month-end project1st of month20 days~28th of month
Quarterly review prep60 days before quarter end30 days30 days before quarter end

Frequently Asked Questions

What counts as a business day?
A business day is Monday through Friday, excluding public holidays. In the US, there are typically 260-261 business days per year (365 days minus ~104 weekend days and ~10 federal holidays).
Does this calculator work for international holidays?
Currently, this calculator supports US federal holidays. For international planning, you can use the calculator without the "exclude holidays" option and manually account for your country's public holidays.
How do milestones work?
When calculating forward or between dates, the calculator shows milestone dates at 25%, 50%, and 75% completion. These help you set check-in points for longer projects.
What if my company has different working days?
If your organization works on weekends or has different days off (such as Sunday-Thursday), uncheck "Exclude weekends" and count calendar days instead. You can manually subtract your actual days off from the total.
Can I calculate deadlines across multiple months or years?
Yes. The calculator handles any date range, whether it's a few days, several months, or multiple years. It accurately accounts for different month lengths and leap years.
Is the start date counted as day 1?
When calculating forward, the start date is day 0 and the next business day is day 1. For example, if you start on Monday and add 1 business day, the deadline is Tuesday. This is the standard convention in project management.

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