Workdays Calculator
Calculate business days between dates excluding weekends. Essential for project management and delivery scheduling.
Reviewed by the Calcura editorial team · Last reviewed
- Question
- How do I count workdays between two dates?
- Answer
- Count all days between the two dates and subtract weekends (Saturdays + Sundays). Then, if your workplace observes holidays, subtract any that fall on a weekday. A standard 52-week calendar year has 260 or 261 workdays before subtracting the 10 or so US federal holidays. Formula: workdays = total_days − weekends − listed_holidays.
▸Show formula & caveatsHide formula & caveats
- Formula
workdays = total_days − weekends − listed_holidays- Caveats
- Monday–Friday is the default workweek, but some industries (retail, healthcare) use different schedules.
- Holiday lists vary by country, state, and company — always apply your own.
- Whether to include the start and end date depends on convention; SLA clocks often run exclusive-to-inclusive.
What This Calculator Does
This calculator counts workdays (Monday–Friday) between two dates by iterating through the span and skipping weekends. It does not subtract holidays — for strict holiday-aware counts, subtract the applicable holiday list manually, or use a payroll or legal-deadline tool. Workday counts answer questions like 'how many billable days are in this quarter?', 'when does a 10-workday SLA expire?', or 'how many workdays before the fiscal year closes?' A standard year has 260 or 261 workdays before subtracting federal holidays.
When To Use This Calculator
Contractor billing and project scoping
A 3-month engagement with start 2026-05-01 and end 2026-07-31 has 65 workdays (before holidays). At $1,000/day, that's a $65k scope before time off is netted out.
SLA or legal deadline tracking
A response due 'within 10 business days' from 2026-04-20 (Monday) is due by 2026-05-01 (Friday). Counting workdays gives the calendar deadline exactly.
Payroll period calculations
A biweekly period with 10 workdays (no holidays) at 8 hours/day is 80 hours of regular time. Subtract holidays that fell in the period for exact pay math.
Project management and Gantt planning
A sprint spanning 2026-04-20 to 2026-05-01 has 10 workdays. Planning to a workday count (rather than calendar days) avoids over-scoping by weekends.
How It Works
Iterate one day at a time from start to end. For each day, check the weekday (0=Sunday, 6=Saturday in JavaScript) — count as a workday if 1–5 (Mon–Fri). Total days = full calendar span from start to end inclusive. Weekends = total − workdays. For spans of 1000+ days, an O(1) formula using (weeks × 5) + remainder gives the same result. US federal calendar has 10 recognized holidays (11 with Juneteenth added in 2021); if any fall on workdays in the range, subtract them from the result.
Formula
For each date D from start to end inclusive:
if D.weekday ∈ {Mon..Fri}: workdays += 1
totalDays += 1
weekends = totalDays − workdaysReal-World Example
Scenario
A PM is scoping a Q3 2026 project running 2026-07-06 through 2026-09-30 and needs to report workday capacity to finance.
Calculation
Calendar span: 87 days inclusive Iterating Mon–Fri count: 64 workdays, 23 weekend days Q3 2026 federal holidays in range: Labor Day (2026-09-07) = 1 Net workdays after holidays: 64 − 1 = 63
Result
63 net workdays of capacity for the quarter. At a 5-person team × 63 days × 8 hours, that's 2,520 person-hours — realistic top-line capacity before PTO and meetings are netted out. Report the raw workday figure and let finance handle their standard PTO deductions separately.
Common Mistakes to Avoid
Mistake: Forgetting to subtract holidays
Solution: This calculator counts all Mon–Fri dates. For US federal workdays, subtract 1 per applicable holiday (New Year's, MLK, Presidents', Memorial, Juneteenth, Independence, Labor, Columbus, Veterans, Thanksgiving, Christmas = up to 11).
Mistake: Treating all countries the same
Solution: Most countries use Mon–Fri, but some Middle Eastern countries use Sun–Thu (notably Israel, some Gulf states historically). For international SLAs, verify the counterparty's workweek.
Mistake: Counting inclusive when the deadline is exclusive
Solution: '10 workdays from Monday' can mean 'the 10th workday after Monday' (excluding Monday itself) or 'Monday plus 10 workdays' (inclusive). Check the contract language — this calculator is inclusive of both endpoints.
Mistake: Conflating workdays with billable days
Solution: Billable days net out PTO, sick time, and holidays. A year has ~260 workdays but typical contractors bill 220–240 days after typical time off. Use workdays for scheduling; use billable days for revenue projection.
Workdays vs. Related Calculators
Business Days Calculator
Uses the same Mon–Fri logic — similar output with a different framing for shipping/banking contexts.
Date Difference Calculator
Counts all calendar days (weekends included). Use when the deadline is in calendar days rather than business days.
Time Zone Converter
If the deadline is defined by the end of a business day in a specific timezone, chain the two calculators: find the workday, then convert its 5 p.m. local to your timezone.
When This Isn't the Right Tool
Holiday-aware workday counts
Use instead: This tool doesn't subtract holidays. For binding deadlines (tax filing, court response, payroll), consult a holiday-calendar-aware tool or manually subtract the relevant holiday count.
Non-standard work schedules
Use instead: Shift workers, healthcare staff, and many hospitality workers don't follow Mon–Fri. For those schedules, use a shift-specific tool or roll your own from the person's actual schedule.
Banking and ACH settlement
Use instead: Use the Federal Reserve's bank-holiday calendar — same-day ACH and wire cutoffs have strict definitions that differ from a general Mon–Fri heuristic.
PTO-adjusted capacity planning
Use instead: Workday totals are gross. For realistic delivery forecasting, net out typical PTO (10–15 days/year in the US) and company holidays, plus expected sick time.
How to Verify This Calculation
In Excel, =NETWORKDAYS(start, end) returns workdays excluding weekends. =NETWORKDAYS(start, end, holiday_range) subtracts a supplied holiday list. Agreement within one day confirms the calculator's output.
Sources
- OPM — Federal Holidays — US Office of Personnel Management: authoritative list of federal holidays and observance rules.
- Federal Reserve — Holiday Schedule — Fed's calendar for bank business days — use when your workday count needs to reflect banking operations.
- US DOL — Hours Worked (FLSA) — Department of Labor on recording work hours and days — relevant for payroll workday calculations.
Reviewed by the Calcura editorial team · Last reviewed