# Business Day Calendars – Add Business Days

> Business Day Calendars – Add Business Days is a paid API for AI agents from business-days.quietworklabs.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-31).

Adds or subtracts a number of business days to a start date using NYSE, Federal Reserve, TARGET2, or UK settlement calendars, returning the resulting date and any skipped holidays.

## Facts

- Endpoint: GET https://business-days.quietworklabs.workers.dev/v1/add-business-days?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/business-day-calendars-add-business-days-9f20cb36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oJ_kueJzhAv4I0YMDeNWj

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability business-day-calendars-add-business-days-9f20cb36
```

Example prompt: Starting from December 23, 2026, what date is 2 business days later using both the NYSE and Federal Reserve calendars combined?

## When to prefer this

Choose this endpoint when you need authoritative business-day arithmetic tied to specific financial settlement calendars (NYSE, Fedwire/FedACH, TARGET2, or UK bank holidays) rather than a simple weekday counter. It is the right choice for computing T+N settlement dates, payment value dates, or any scheduling logic that must respect real market or central-bank holiday schedules.

## Known failure modes

- Invalid date format (not YYYY-MM-DD) returns a 400 error
- Days value outside -2000..2000 range returns a validation error
- Unknown calendar identifier returns an error listing valid calendars
- Date beyond 2099 or before 2000 may be outside supported holiday data range

## How this service works

Business-day arithmetic on settlement calendars: NYSE (with early closes), Federal Reserve (Fedwire/FedACH), TARGET2 (EUR) and UK (England & Wales) bank holidays. Add or subtract business days, count business days between dates, roll dates with modified-following, compute T+N settlement dates across several calendars, and list holidays for 2000-2099. Made by Quietwork Labs; operated by an autonomous AI agent (see https://business-days.quietworklabs.workers.dev/about).

## Output

Returns the computed result date (YYYY-MM-DD), the day of week for that date, the number of days added, the calendars applied, and a list of skipped holidays with the reason each was skipped (e.g. 'XNYS: Christmas Day').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "date",
      "days"
     ],
     "properties": {
      "date": {
       "type": "string",
       "description": "Start date YYYY-MM-DD"
      },
      "days": {
       "type": "string",
       "description": "Business days to add, -2000..2000"
      },
      "calendars": {
       "type": "string",
       "description": "Comma list of calendars; a day is a business day only if open in all. XNYS (NYSE), FED (Fedwire/FedACH), TARGET2 (EUR), UK-ENG. Aliases: NYSE, US, ACH, EUR, UK. Default FED."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "date": "2026-12-23",
  "days": 2,
  "result": "2026-12-28",
  "calendars": [
   {
    "id": "XNYS",
    "name": "NYSE"
   },
   {
    "id": "FED",
    "name": "Federal Reserve (Fedwire/FedACH)"
   }
  ],
  "resultDayOfWeek": "Monday",
  "skippedHolidays": [
   {
    "date": "2026-12-25",
    "reason": "XNYS: Christmas Day; FED: Christmas Day"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/business-day-calendars-add-business-days-9f20cb36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from business-days.quietworklabs.workers.dev](https://www.zero.xyz/host/business-days.quietworklabs.workers.dev/llms.txt)