Working Days Between Dates
Measure elapsed business days rather than calendar days.
What this solves
Calculate supplier working-day lead time. This pattern is useful when the business question is clear but a generic tutorial is too abstract.
The rule
=NETWORKDAYS(start_date,end_date,[holidays])
=NETWORKDAYS(B2,C2,Holidays!A:A)Google Sheets: The core pattern is also usable in Google Sheets; exact function support and locale separators can differ.
Real-work checklist
- Define the business key and expected grain before writing the formula, query or markup.
- Test the pattern on a small known sample where you can verify the answer manually.
- Check missing values, duplicates and data types before trusting a large result.
- Scale to the real file or database only after the logic is proven.
Common mistake
Weekend definitions and plant shutdowns may require NETWORKDAYS.INTL or a custom holiday calendar.