What this calculator does
The Add Business Days to a Date Calculator takes a start date and a number of business (working) days, then advances the date forward, counting only Monday through Friday. Saturdays and Sundays are skipped automatically. It returns the resulting date, the day of the week it falls on, how many weekend days were skipped, and the total number of calendar days that elapsed.
This tool counts Saturday and Sunday as non-working days. It does not account for public or bank holidays, which vary by country and region — if you need holiday-aware scheduling, subtract any holidays that fall within the result period manually.
How to use it
Enter the start year, month (1-12), and day (1-31). Then enter the number of business days you want to add and submit. The result shows the final date and its weekday, so you can quickly see, for example, when a "net 10 business days" deadline lands.
How the formula works
The calculation steps one calendar day forward at a time. Each time it lands on a weekday (Mon-Fri) it increments the count of business days added; when it lands on a weekend it skips that day without counting it. The loop stops as soon as the requested number of business days has been reached. The total calendar days is simply the business days plus the weekend days that were skipped.
$$\text{Result} = \text{Start} + (\text{business days, skipping Sat \& Sun})$$
$$\text{count day} \iff \text{weekday} \notin \{\text{Sat}, \text{Sun}\}$$
$$\text{calendar days} = \text{business days} + \text{weekend days}$$
Worked example
Start date: Monday, 2024-01-01. Add 5 business days. Counting forward: Tue Jan 2 (1), Wed Jan 3 (2), Thu Jan 4 (3), Fri Jan 5 (4), then Sat/Sun are skipped, then Mon Jan 8 (5). The result is Monday, 2024-01-08, with 2 weekend days skipped and 7 total calendar days.
$$\text{calendar days} = 5 + 2 = 7$$
Business Days Added Across Different Start Days
The same number of business days produces a different result depending on which weekday you start from, because the number of intervening weekends changes. The table below uses a fixed count of +5 business days and a concrete week (Monday 6 January 2025 through Friday 10 January 2025) so you can see the pattern clearly. "Weekend days skipped" counts Saturdays and Sundays that fall inside the span; "total calendar days" is the difference between the start date and the result date.
| Start date | Start weekday | Add | Result date | Result weekday | Weekend days skipped | Total calendar days |
|---|---|---|---|---|---|---|
| 2025-01-06 | Monday | 5 | 2025-01-13 | Monday | 2 | 7 |
| 2025-01-07 | Tuesday | 5 | 2025-01-14 | Tuesday | 2 | 7 |
| 2025-01-08 | Wednesday | 5 | 2025-01-15 | Wednesday | 2 | 7 |
| 2025-01-09 | Thursday | 5 | 2025-01-16 | Thursday | 2 | 7 |
| 2025-01-10 | Friday | 5 | 2025-01-17 | Friday | 2 | 7 |
Notice that adding exactly 5 business days always advances the weekday by a full week, landing on the same weekday and skipping one weekend (2 days), for a total of 7 calendar days. The picture changes once the count is not a multiple of 5 — see the worked examples below.
FAQ
Does it include the start date? No. The count begins on the next day, so adding 1 business day to a Friday lands on the following Monday.
Are holidays handled? No — only Saturdays and Sundays are excluded. Adjust manually for holidays relevant to your region.
What if I enter 0 business days? The result is the start date itself, unchanged.
