Calendaring Calculator
Calendaring calculator works out Working days and Calendar days from Start date, Deadline period and Deadline period unit. The default figures on this page give result date of 2024-01-22; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
4 steps
- Weekend: Saturday and Sunday (5 working day(s) a week).
- Holiday calendar: US federal holidays (5 U.S.C. 6103).
- Exclude the trigger day 2024-01-01 and count 21 days forward: that reaches 2024-01-22.
- 2024-01-22 is a working day, so no roll is needed.
Holidays in the spantable
Its 7 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
5 sources
Keep this result
Save it, change one figure, then compare the two
The calculation stays free. Save this scenario, adjust one assumption, save that too, and put them side by side to see exactly what the change costs you. A free account keeps 5 scenarios and 2 comparisons; Personal makes both unlimited and adds exports and private links. Nothing is saved unless you press Save.
What the calendaring calculator calculates
Counts working days between two dates, adds or subtracts a number of working days from a date, and rolls a deadline forward to the next working day under the Rule 6(a) convention.
How to use this calendaring calculator
Enter Start date, Deadline period, Deadline period unit and Deadline counts. Working days updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Working days, Calendar days and Weekend days in the span.
The method follows Microsoft Excel NETWORKDAYS.INTL function specification, Microsoft Excel WORKDAY.INTL function specification, Federal Rules of Civil Procedure, Rule 6(a) and 6(d), 5 U.S.C. 6103 - Federal legal public holidays and 34 CFR 300.301(c)(1)(i) - Initial evaluations under the Individuals with Disabilities Education ACT.
What you can compare
Change one input at a time to see how it affects Working days, Calendar days and Weekend days in the span. The inputs you can vary are Start date, Deadline period, Deadline period unit, Deadline counts, The period runs and Roll a weekend or holiday deadline to the next working day.
Understanding Working days, Calendar days and Weekend days in the span
Holiday calendars differ by employer, court and country. Confirm the applicable holiday list and, for a legal deadline, the governing rule before relying on this date.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What information do I need for the calendaring calculator?
You need Start date, Deadline period, Deadline period unit, Deadline counts, The period runs, Roll a weekend or holiday deadline to the next working day, Weekend and Holiday calendar. The page opens with default figures that give result date of 2024-01-22, so you can see the scale before entering your own.
What does this calendaring calculator show?
It shows Working days, Calendar days, Weekend days in the span, Holidays excluded, Holidays in the span, Result date, Result date falls on and Date before any roll-forward, with the working and any warnings for your entries.
Can I check how the calendaring calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.