T+N: add business days

GET /v1/business-days/add

T+N: move N business days (N can be negative; N=0 checks the date itself).

Parameters

Name	In	Type	Default	Description
date (required)	query	string	—	YYYY-MM-DD, or today in the tz time zone
n (required)	query	string	—
calendars (required)	query	string	—	Comma-separated calendar ids, at most 10, e.g. USD,AUD or XNYS,JP:bank
mode	query	all | any	all	all: a business day in every calendar (settlement). any: in at least one.
tz	query	string	UTC	IANA time zone that resolves today, e.g. America/New_York. Default UTC.
format	query	json | csv | text	json	text: the bare result

Example

curl "https://api.financecalendarapi.com/v1/business-days/add?date=2027-12-23&n=2&calendars=USD,XNYS"

Response, captured from the live API when this page was built:

{
  "data_release": {
    "id": "20261016T064343Z",
    "library_version": "0.106",
    "generated_at": "2026-10-16T06:45:33+00:00"
  },
  "date": "2027-12-23",
  "n": 2,
  "result": "2027-12-28",
  "mode": "all",
  "coverage": "verified",
  "estimated": false
}

Errors use problem details. Every response says which data release answered it, in data_release and the x-data-release header.