Calculate

Add business days to a date

POST/v1/calculate/date/add/business_days

Moves a date forward (or back, with a negative number) by business days, skipping weekends and the holidays you send. The start date is not counted and 0 returns it unchanged.

Updated October 27, 2026

Request body

Name	Type	Required	Description
weekend	array of integer	no	ISO weekday numbers that are not business days: 1 is Monday, 7 is Sunday. Default Saturday and Sunday
holidays	array of string	no	ISO dates that are not business days. Holidays are sent by the caller: no country calendar is built in
date	string	yes	An ISO date or ISO date and time
days	integer	yes	Business days to add; negative goes back. The start date is not counted and 0 returns it unchanged

Example request

A request body that works, as JSON.

{
  "date": "2026-10-16",
  "days": 5
}

Code samples

Replace YOUR_TOKEN with your access token.

curl

curl -X POST 'https://api.skillfulsardine.com/v1/calculate/date/add/business_days' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "date": "2026-10-16",
  "days": 5
}'

PowerShell

$body = @'
{
  "date": "2026-10-16",
  "days": 5
}
'@
$response = Invoke-RestMethod -Method Post -Uri 'https://api.skillfulsardine.com/v1/calculate/date/add/business_days' `
  -Headers @{ Authorization = 'Bearer YOUR_TOKEN' } `
  -ContentType 'application/json; charset=utf-8' `
  -Body ([System.Text.Encoding]::UTF8.GetBytes($body))
$response | ConvertTo-Json -Depth 10

Python

import requests

payload = {
    "date": "2026-10-16",
    "days": 5,
}

response = requests.post(
    "https://api.skillfulsardine.com/v1/calculate/date/add/business_days",
    headers={"Authorization": "Bearer YOUR_TOKEN"},
    json=payload,
    timeout=30,
)
print(response.json())

JavaScript

const response = await fetch("https://api.skillfulsardine.com/v1/calculate/date/add/business_days", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_TOKEN",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
  "date": "2026-10-16",
  "days": 5
}),
});
const result = await response.json();
console.log(result);

Node

// Node 18 or later. Save as call.mjs and run: API_TOKEN=... node call.mjs
const token = process.env.API_TOKEN;

const response = await fetch("https://api.skillfulsardine.com/v1/calculate/date/add/business_days", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${token}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
  "date": "2026-10-16",
  "days": 5
}),
});
const result = await response.json();
console.log(result);

Rust

// Cargo.toml: reqwest = { version = "0.12", features = ["blocking", "json"] }, serde_json = "1"
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let body: serde_json::Value = serde_json::from_str(r#"{
  "date": "2026-10-16",
  "days": 5
}"#)?;
    let response = reqwest::blocking::Client::new()
        .post("https://api.skillfulsardine.com/v1/calculate/date/add/business_days")
        .bearer_auth("YOUR_TOKEN")
        .json(&body)
        .send()?;
    println!("{}", response.text()?);
    Ok(())
}

Swift

import Foundation

var request = URLRequest(url: URL(string: "https://api.skillfulsardine.com/v1/calculate/date/add/business_days")!)
request.httpMethod = "POST"
request.setValue("Bearer YOUR_TOKEN", forHTTPHeaderField: "Authorization")
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = Data(#"""
{
  "date": "2026-10-16",
  "days": 5
}
"""#.utf8)

let (data, _) = try await URLSession.shared.data(for: request)
print(String(decoding: data, as: UTF8.self))

Response

The fields inside data of a successful response.

Name	Type	Required	Description
date	string	yes	The resulting date, as an ISO date
weekday	string	yes	Its weekday name in English

Example response

A real answer from the operation, as JSON. The fields in the table above are inside data.

{
  "data": {
    "date": "2026-10-23",
    "weekday": "Friday"
  },
  "errors": null,
  "meta": {
    "request_id": "1440a4d7-fd2f-4719-896c-99dd59c4df5c",
    "timestamp": "2026-10-27T07:19:42.090900Z",
    "version": "2026-03-26"
  },
  "pagination": null
}

Responses

Status	When it happens
200	Successful Response
400	The body respects the operation schema, but the use case rejected it. Each problem is one ApiError entry
413	The request is larger than the request size limit of the API allows
422	The body does not respect the operation schema. Each problem is one ApiError entry with the code validation_error
500	Something failed inside the server and was not an input problem. The same envelope, errors may be empty