Subtracting dates gives a calendar difference
B2-A2 does not count eligible dates and excludes the inclusive endpoint rule.
Count eligible dates between two endpoints
About this lesson
Count both endpoints when they are working dates, preserve the sign of reversed intervals, and avoid double-counting closures.
Task requirements
Fill C2:C5 with the signed number of eligible dates from column A through column B, including both endpoints when they are working dates. Apply the text weekend mask in G2 and closure dates G4:G7. Reversing the interval reverses the sign; an all-closed weekly mask returns zero.
Teaching · read-only worksheet ·
Step 1 / 5Read both endpoints
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Inspect the highlighted cells. This step has no automatic change to apply. Teaching is read-only; switch to Your turn to edit.
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Follow the highlighted cells. Switch to Your turn to edit. Answer cells: C2, C3, C4, C5. Browser calculations may differ from your Excel version.
Apply your first formula, then fill the answer range. Relative references move; $-locked references stay put.
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THE QUICK ANSWER01
NETWORKDAYS.INTL counts an inclusive date interval after removing weekly closures and holiday dates. It returns a negative count when the start follows the end.
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=NETWORKDAYS.INTL(A2,B2,$G$2,$G$4:$G$7)For the example data
C2 2C3 -2C4 0C5 0
The formula uses the interactive worksheet above. Adjust ranges and criteria for your own data.
How it works
A duration counter is not an offset calculator
NETWORKDAYS.INTL counts eligible dates including both endpoints. WORKDAY.INTL moves away from a start. Advancing one workday and counting the inclusive interval can therefore produce two working dates.
Accepted dates and range size
Use whole numeric dates from 2000-01-01 through 2099-12-31 and intervals of at most 3,660 calendar days. The seven-character text mask may close every weekday. Closure cells may be blank or whole numeric dates; no jurisdiction holiday rules are assumed.
Read the full step-by-step walkthrough
- Read both endpoints
Eligible start and end dates both count. A one-date interval can therefore return one, while a weekend-only interval can return zero.
- Declare the weekly calendar
Use the same Monday-first text convention as the deadline task. NETWORKDAYS.INTL also accepts 1111111 and counts no eligible dates.
- Remove closure dates without double subtraction
The closure list is a set of excluded dates. Duplicate entries and a closure already on a weekly closed day do not remove additional dates.
- Preserve the interval sign
Do not sort the endpoints or wrap the result in ABS. The reversed case deliberately asks for a signed count.
- Fill and check boundary cases
Lock the calendar references, fill C2 down, and check one-day, reversed, all-closed and leap-day intervals.
Things to watch
An absolute count loses direction
ABS hides a reversed interval. This task explicitly retains its sign.
Subtracting every holiday row overcounts exclusions
A duplicate closure or a weekend holiday must not reduce the count twice.
About this example
Formula entry, filling, all authored datasets, walkthrough controls and original/current/frozen XLSX downloads were checked in Chrome on October 17, 2026. Dates remain numeric Excel 1900-system serials with readable formatting. Closure dates are invented office-calendar examples. Native Excel and Google Sheets recalculation remain unverified.
Content version 1. Practice checks compare calculated results across different datasets; they do not certify every possible formula.