Working Days Calculator

How do I calculate working days, or add business days to a date?

AnyTool Working Days Calculator does two things in your browser. In Count mode, enter a start and end date and it instantly shows how many working days fall between them — counting both ends, the same inclusive convention as Excel’s NETWORKDAYS. In Add mode, enter a date and a number of working days (use a negative number to subtract) and it returns the resulting calendar date and its weekday, skipping weekends and holidays the way Excel’s WORKDAY does. You choose exactly which days count as your working week (Monday–Friday by default, but Sunday–Thursday, a four-day or six-day week all work) and add your own holiday dates. Nothing is uploaded.

Count working days between two dates (both ends included)
Add or subtract working days to get a resulting date and weekday
Configurable working week — not just Monday to Friday
Add your own holidays; weekends and holidays are skipped
100% in your browser — no upload, no signup, works offline

What is

Working day

A working day (or business day) is a day on which normal business is conducted — typically Monday to Friday, excluding weekends and public holidays. Counting working days between two dates follows the inclusive NETWORKDAYS convention, where both the start and the end date are counted. A related operation adds or subtracts a number of working days to a date: starting the day after the given date, you step forward (or backward) one calendar day at a time, skipping any weekend or holiday, until the required number of working days has passed — the WORKDAY convention. Because weekends and holidays differ by country and organisation, both depend on the working week and holiday list you define.

Calculators

Related terms

Business dayNETWORKDAYSWORKDAYPublic holiday

Frequently Asked Questions

The number of working days between two dates is the count of days in your working week — Monday to Friday by default — from the start date to the end date inclusive, with any holiday that lands on a working day removed. AnyTool Working Days Calculator shows that total live as you type, lists the non-working (weekend) days separately, and tells you which weekday each date falls on. Both the start and end date are counted, matching the NETWORKDAYS function in Excel and Google Sheets.

Count every day from the start to the end date that is in your working week and is not a holiday; both the start and end date are included.

To add business days, pick the start date and enter the number of working days in Add mode; the calculator steps forward day by day, skipping any weekend or holiday, and stops once it has counted that many working days, showing the resulting calendar date and its weekday. The start date itself is not counted, the same as Excel’s WORKDAY function. Enter a negative number to subtract working days and find a date that many business days earlier — useful for working back from a deadline.

Switch to Add mode, enter the start date and how many working days to add, and the calculator skips weekends and holidays to give the resulting date.

AnyTool lets you choose any working week using day toggles, so Monday–Friday, Sunday–Thursday, a four-day week or a six-day week all work. You can also add custom holiday dates. Public holidays are not built in because they vary by country, region and year, so you add the ones relevant to you. Whatever you set is used by both modes — counting working days between dates and adding or subtracting them.

Yes — toggle exactly which days count as working days and add any holiday dates; both apply to counting and to adding or subtracting.

Counting includes both end dates and adding never counts the start date, the conventions used by Excel’s NETWORKDAYS and WORKDAY functions, and all arithmetic is done in UTC to avoid daylight-saving jumps. Because the tool reads your device’s calendar, your time zone can shift what counts as a boundary day near midnight. Your dates and holidays are never sent to a server; the page works offline after first load.

It uses the same inclusive NETWORKDAYS and WORKDAY conventions as spreadsheets and uploads nothing — every calculation runs in your browser.

Count the working (business) days between two dates, or add and subtract working days to a date to get a resulting calendar date and its weekday — with a configurable working week and your own holidays, all in your browser.

Features

Count working days between two dates (both ends included)
Add or subtract working days to get a resulting date
Configurable working week, not just Monday–Friday
Custom holidays skipped in both modes
Shows the weekday of each date — 100% client-side

PriceFree

CategoryCalculator

PlatformAll (browser-based)

PrivacyYour dates never leave your device

Input: Start date, End date or number of working days, Working-week selection, Optional custom holidays

Output: Working-day count, Resulting calendar date and weekday, Non-working days and holidays skipped

Detailed Explanation

Methodology

Counting Working Days Between Two Dates

In Count mode, AnyTool Working Days Calculator reports how many working days fall between a start and an end date using the inclusive NETWORKDAYS convention: both the start and the end date are counted, so a Monday-to-Friday range is five working days. A pure, clock-free engine walks the span one calendar day at a time and tallies a day as working when its weekday is in the working week you selected and the date is not in your holiday list; everything else is counted as a non-working (weekend) day. The page decides what “today” is for the default date and hands plain calendar dates to the engine, which does all arithmetic in UTC to stay immune to daylight-saving shifts. Reversed dates are detected and swapped before counting.

Both start and end dates are counted (NETWORKDAYS-style)
A day counts when its weekday is in your working week
Holidays on a working day are excluded from the total
Non-working days are reported separately
Engine is clock-free and unit-testable — the page supplies the dates

Use Cases

Adding and Subtracting Working Days

The differentiator is Add mode: give a start date and a number of working days and the calculator returns the resulting calendar date and its weekday, skipping every weekend and holiday on the way. Following Excel’s WORKDAY convention, the start date itself is not counted, the step begins the next day, and the result always lands on a working day. A positive number moves forward; a negative number moves backward, which is ideal for working back from a deadline to find the latest safe start date. The tool also reports how many calendar days the result is away and how many weekend days and holidays were skipped, so the shift is fully transparent.

Add or subtract N working days to/from any date
Start date is not counted; result lands on a working day
Negative numbers step backward from a deadline
Weekends and holidays are skipped automatically
Reports calendar days spanned and days skipped

How It Works

Configurable Working Week and Custom Holidays

Both modes are driven by a working week you define with simple day toggles, indexed Sunday through Saturday, so Monday–Friday (the default), Sunday–Thursday, a four-day or a six-day week all work for any region or schedule. Custom holiday dates are matched on the calendar date only and apply to both counting and stepping. No national or public holidays are built in because they vary by country, region and year, so the result is only as complete as the holidays you add — a deliberate, honest design choice that keeps the math correct everywhere.

Working week is fully configurable, not fixed to Mon–Fri
Presets for Mon–Fri, Mon–Thu and Sun–Thu
Custom holidays apply to both modes
No built-in public holidays — users add their own
Correct for any country or working schedule

Privacy & Security

Privacy, Time Zones and Limits

Every calculation runs in the browser, so the dates and holidays you enter are never sent to a server, there is no account or tracking, and the page works offline after first load. All arithmetic is done in UTC to avoid daylight-saving jumps, but because the tool reads your device’s calendar, your time zone can shift what counts as a boundary day near midnight. The business-day figure is only as complete as the working week and holiday list you provide.

Dates and holidays never leave your device
No signup, no tracking; works offline after first load
UTC arithmetic avoids daylight-saving errors
Time zone can shift a boundary day near midnight
Accuracy depends on the week and holidays you set

Working days: in-browser (AnyTool) vs typical online business-day calculators
Capability	AnyTool	Typical online calculators
Processing	Runs in your browser	Often server-side
Count between dates	Inclusive NETWORKDAYS-style	Usually supported
Add / subtract working days	Yes — both directions	Sometimes missing
Working week	Any pattern you toggle	Often fixed Mon–Fri
Custom holidays	Add your own to skip	Sometimes country presets only
Resulting weekday	Shown	Sometimes missing
Reversed dates	Auto-swapped	Sometimes errors
Works offline	Yes (PWA)	No
Cost / signup	Free, no signup	Often ad-heavy or gated

AnyTool counts and shifts working days locally and uploads nothing.

Cite This Page

Title: Working Days Calculator (count business days between dates, add/subtract working days, custom week + holidays, no server)
Author: AnyTool
Published: January 1, 2026
Modified: February 8, 2026
Section: Calculators
URL: https://www.anytool.tech/working-days-calculator

Formatted Citation

AnyTool. "Working Days Calculator (count business days between dates, add/subtract working days, custom week + holidays, no server)." AnyTool, January 1, 2026. https://www.anytool.tech/working-days-calculator

A privacy-first, 100% client-side working-days calculator built on a pure, clock-free, unit-tested engine. It performs two operations with a fully configurable working week and a custom holiday list. In Count mode it reports how many working days fall between a start and an end date using the inclusive NETWORKDAYS convention, where both the start and end date are counted, so a Monday-to-Friday range is five working days; it also reports the non-working days and the weekday each date falls on. In Add mode — the key differentiator from a plain date-difference tool — it adds or subtracts a number of working days to or from a start date, skipping every weekend and holiday, and returns the resulting calendar date and its weekday following Excel’s WORKDAY convention in which the start date itself is not counted; negative numbers step backward from a deadline. The working week is defined with day toggles indexed Sunday through Saturday, so Monday–Friday, Sunday–Thursday, four-day and six-day weeks all work for any region. No public holidays are built in because they vary by country and year, so users add the dates that matter to them and the result is only as complete as that list. Reversed dates are swapped automatically, all arithmetic is done in UTC to avoid daylight-saving jumps, and because the tool reads the device calendar the time zone can shift a boundary day near midnight. Every calculation is a pure function that runs entirely in the browser, nothing is uploaded, and the page works offline after first load.