Project Deadline Calculator (Working Days, US Holidays)
Working days from a start date. Skips weekends and US federal holidays.
What this tool does
Adds (or subtracts) working days to a start date and shows the resulting calendar date. Skips Saturdays and Sundays automatically. Optionally skips US federal holidays for the year(s) involved (New Year's Day, MLK Day, Presidents Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, Christmas), shifted to Friday or Monday when they fall on a weekend per US federal observance rules. Calculation is local; nothing is uploaded.
How to use it
Enter the start date and the number of working days. Pick direction: Forward calculates a deadline from today. Backward tells you the latest start date to hit a target. Toggle the holiday checkbox to account for federal holidays. Press Calculate. Example: 20 working days forward from a date in early January with holidays counted produces a late-January or early-February deadline (one or two holidays may fall in the window).
Common use cases
- Setting a contractually-defined deadline that says "30 business days from execution."
- Working backward from a launch date to figure out the latest acceptable kickoff.
- Estimating SLA windows for support response or refund processing.
- Planning a sprint that should end before a known holiday week.
- Checking whether a "5 working days" turnaround crosses a holiday and is actually 7 calendar days.
Common pitfalls
- "Business day" varies by country. This tool implements US federal holiday rules. UK, EU, India, Japan, Australia all have different lists. Toggle the holiday option off if the contract specifies a different country.
- State and local holidays. US federal holidays are not the same as state holidays or industry conventions. The financial industry observes a few extra closures (Good Friday, Day After Thanksgiving). Adjust by hand if needed.
- Weekend observance. Federal holidays falling on a Saturday move to Friday; Sunday holidays move to Monday. The tool follows this rule. State and private-sector practices sometimes differ.
Frequently asked questions
- What counts as a "working day" here?
- Any weekday (Monday through Friday). When the holiday option is on, the tool also subtracts US federal holidays observed in the year(s) involved. Holidays falling on a Saturday move to the prior Friday; holidays falling on a Sunday move to the following Monday, per US federal observance rules.
- Why does my international deadline not match?
- This tool implements US federal holidays only. UK has bank holidays (Boxing Day, Spring and Summer bank holidays). EU countries each have their own list. Japan has 16 national holidays. India and China have very different lists. For international contracts, turn off holiday skipping and add the correct country list manually.
- Does this account for state holidays or industry conventions?
- No. Federal holidays only. Some states observe additional days (Patriot Day in Massachusetts, Cesar Chavez Day in California). Some industries close on extra days: financial markets close on Good Friday and the day after Thanksgiving. For state or industry-specific deadlines, adjust by hand.
- What is the difference between forward and backward direction?
- Forward calculates the deadline given a start date and a number of working days. Backward calculates the latest acceptable start date given a target deadline. Useful when working backward from a launch: the launch is on a fixed date; you need 30 working days; what is the latest acceptable kickoff?
- Why does adding 5 working days sometimes give 7 calendar days, sometimes 9?
- Weekends always add 2 calendar days for every 5 working days that span them. Holidays add an additional calendar day each. So 5 working days starting Monday with no holidays equals exactly 7 calendar days; 5 working days that span Thanksgiving equals 8 or 9 calendar days depending on which weekday Thanksgiving falls on.
- Is the start date itself counted as a working day?
- No. The start date is the day before the count begins. Counting starts on the next working day after the start date and proceeds until N working days have elapsed. If you want to count the start date itself, subtract 1 from your working-days input (use 19 instead of 20).
Cite this tool
For academic, journalistic, or technical references. Pick a format:
Citations use 2026 as the publication year. Access date is left as a fillable placeholder where the citation style expects one.