Add Working Days Calculator
The date a given number of working days from a start date, skipping weekends.
Results
Resulting date
9 Oct 2026
Day of the week
5
Days
21
ISO week number
41
What this tool does
Contracts, notice periods and delivery promises are almost always written in working days, and counting them on a calendar by hand is where mistakes creep in. Enter a negative number to count backwards and find the date you would have to start on.
Formula
counts working days only, starting from the given date
Variables
| Symbol | Meaning | Unit |
|---|---|---|
start_date | Start date | — |
workdays_to_add | Working days to add | — |
date | Resulting date | — |
weekday | Day of the week | — |
calendar_days | Days | — |
week | ISO week number | — |
Worked example
- Start date2026-09-18
- Working days to add15
- Resulting date9 Oct 2026
- Day of the week5
- Days21
- ISO week number41
Limitations
- Only Saturdays and Sundays are excluded. Public holidays differ by country and are not deducted.
- Dates are handled as calendar dates. Time zones, daylight saving changes and public holidays are not taken into account.
Frequently asked questions
Are public holidays taken into account?
No. Only Saturdays and Sundays are skipped, because public holidays differ by country, region and sometimes by city. Count the holidays that fall inside the period yourself and add them to the number of working days before calculating.