# Business Day Calendars – Count Business Days Between Dates

> Business Day Calendars – Count Business Days Between Dates 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).

Returns the number of business days between two dates for one or more settlement calendars (NYSE, FED, TARGET2, UK), including a list of holidays in the range.

## Facts

- Endpoint: GET https://business-days.quietworklabs.workers.dev/v1/business-days-between?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-count-business-days-between-dates-4214b58a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NpKs8RiUluYV9HZcxPT4L

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-count-business-days-between-dates-4214b58a
```

Example prompt: How many Federal Reserve business days are there between January 1, 2026 and December 31, 2026? Don't count the start date.

## When to prefer this

Use this endpoint when you need to count the exact number of business days between two dates according to a specific financial settlement calendar (NYSE, FED/ACH, TARGET2, or UK). Prefer it over generic weekday counters when holiday accuracy for regulated markets matters — e.g. for T+N settlement, payroll scheduling, or regulatory deadline calculations. Covers 2000–2099.

## Known failure modes

- Missing required start or end date parameters returns a 400 error
- Invalid date format (non-YYYY-MM-DD) causes a parse error
- Unrecognized calendar alias returns an error or defaults to FED
- End date before start date may return 0 or an error
- Payment failure (x402) blocks access if USDC not provided

## 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

A JSON object containing the start and end dates, the list of calendars used, the inclusive flag, the total count of business days in the range, and an array of holiday dates (YYYY-MM-DD) that fell within the range.

## 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": [
      "start",
      "end"
     ],
     "properties": {
      "end": {
       "type": "string",
       "description": "End date YYYY-MM-DD"
      },
      "start": {
       "type": "string",
       "description": "Start date YYYY-MM-DD"
      },
      "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."
      },
      "inclusive": {
       "type": "string",
       "description": "true to count the start date too"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "end": "2026-12-31",
  "start": "2026-01-01",
  "calendars": [
   {
    "id": "FED",
    "name": "Federal Reserve (Fedwire/FedACH)"
   }
  ],
  "inclusive": false,
  "businessDays": 251,
  "holidaysInRange": [
   "2026-01-19",
   "2026-02-16"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/business-day-calendars-count-business-days-between-dates-4214b58a/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)