WORKDAY.INTL in ONLYOFFICE: Custom Weekend Deadlines

It advances or backs up from a date by a count of working days. Use it for inventory receiving dates, fulfillment deadlines, scheduled follow-up work and service calendars that do not necessarily close on Saturday/Sunday. A positive offset moves forward; a negative offset moves backward. Unlike NETWORKDAYS.INTL, it returns a date value, not a number of workdays between two dates.

=WORKDAY.INTL(start_date, days, [weekend], [holidays])

ONLYOFFICE’s dedicated reference explicitly documents the first two parameters, optional third/fourth parameters and their order, but not every conversion rule or error code. Use commas as illustrated in the English ONLYOFFICE documentation; if a different region uses another separator in the editor, follow the target editor’s input tooltip instead of blindly changing the function’s meaning.

All officially documented weekend codes

Custom weekend strings have seven 0/1 positions for Monday through Sunday: "0000011" marks Saturday/Sunday off; "0000110" marks Friday/Saturday off; "1000001" marks Monday/Sunday off. The ONLYOFFICE article rules out "1111111" (every day off). It does not establish the exact native error code for every invalid mask.

The fixtures below use real dates generated by DATE, making them independent of locale-specific text parsing:

Format A2/B2/D2/D3 as dates. Enter the following test formulas into unused cells. The outputs are ISO-formatted expected calendar dates from a separate Python date model; they are not native ONLYOFFICE outputs.

Manual count: starting Friday October 9, the next five ordinary weekdays are Monday 12, Tuesday 13, Wednesday 14, Thursday 15 and Friday 16. With both Monday 12 and Monday 19 marked as company holidays, five valid weekdays are Tuesday 13, Wednesday 14, Thursday 15, Friday 16 and Tuesday 20. With Friday/Saturday weekends and the same holidays, Sundays 11 and 18 become working days. These examples deliberately show why merely shifting a date by seven calendar days is not a correct substitute.

Enter a documented weekend code in E2 (say 7 for Friday/Saturday), and a whole-number workday offset in F2 (say 5). Keep the actual holiday dates in D2:D3. Your formula can then be changed without rewriting every function:

=WORKDAY.INTL($A$2,F2,$E$2,$D$2:$D$3)

With E2=7, F2=5 and the two Monday closures, the independently expected date is 2026-10-18 (Sunday). Yes, Sunday is a workday in this example; the business is off Friday/Saturday. For a date-only result, format the result cell as Date. A cell displayed as a large serial integer may simply need formatting; do not alter the formula to force an arbitrary string representation until the date system is checked.

For a reverse scheduling case, set F2 to -5. With E2=7 and no excluded dates in the backward interval, independently expect 2026-10-04 (Sunday). This illustrates the sign of the offset, rather than an assertion that ONLYOFFICE Desktop has executed the case successfully.

Compare the result with WORKDAY and NETWORKDAYS.INTL

WORKDAY uses the standard Saturday/Sunday schedule and its optional holidays occupy the third position, according to the ONLYOFFICE WORKDAY help. WORKDAY.INTL allows other weekends and puts holidays fourth. NETWORKDAYS.INTL counts workdays inside an interval, rather than returning a shifted deadline, according to the ONLYOFFICE NETWORKDAYS.INTL reference.

• Wrong deadline when closure days are involved: Put the holiday list in argument four. Omitting the weekend parameter but writing the holiday range third confuses a weekend selector with a date range.
• Friday/Saturday operations: Use code 7 or "0000110"; code 1 still means Saturday/Sunday regardless of the local workweek.
• Sunday is unexpectedly selected: For code 7 Sunday is working. Choose your actual business schedule rather than assuming Saturday/Sunday are universally excluded.
• Date printed as a number: Format the result as a Date and check workbook date-system settings. Serial representation does not establish whether the time/calendar meaning is correct.
• A holiday appears to be ignored: Ensure it is a real date and inside the relevant forward/backward path; if it is already a weekend, skipping it twice has no additional effect.
• Noninteger offsets (e.g. 2.8), zero, blanks, text and invalid date serials: The short ONLYOFFICE reference does not specify the complete conversion/error behavior. Microsoft’s Excel article documents additional rules, but do not import them as proven ONLYOFFICE outcomes. Native tests are needed before relying on these edge cases.
• Malformed masks: A weekend string must contain exactly seven 0/1 characters, beginning with Monday. The all-ones mask is explicitly invalid in the official ONLYOFFICE guide; the native error presentation needs checking.
• Dates are read in the wrong month: Avoid localized text parsing where possible; use DATE(year,month,day) inputs and apply a clearly identified displayed date format. When copying imported Excel files, verify the date system (1900 or 1904), locale and holiday-list conversion in the target ONLYOFFICE build.
• Backward calculations: A negative workday offset walks backward one valid workday at a time. A calendar date earlier than A2 is not automatically an error; check the sign and nonworking-day settings first.

The Microsoft Excel WORKDAY.INTL documentation lists the same argument order and weekend-code mapping. That supports syntax-level cross-compatibility. It does not establish identical results for all legacy files, formats, date-system settings or erroneous data. The ONLYOFFICE function catalogue includes WORKDAY.INTL; the Formula tab guide illustrates both online and Desktop interfaces. Neither gives a reliable release-by-release feature matrix. This guide records current unversioned documentation coverage as of 2026-10-13, and labels native ONLYOFFICE web/Desktop compatibility not yet verified.

Native Desktop/web execution, localized input, date-system settings and valid/invalid-mask boundaries remain untested. Verify the cases relevant to your own schedule in the installed editor.

Sources accessed 2026-10-13: WORKDAY.INTL official syntax / codes / masks; NETWORKDAYS.INTL comparison; original WORKDAY syntax; Spreadsheet Editor function catalogue; Excel comparator.