# Darwin Business Calendar – Business Days Counter

> Darwin Business Calendar – Business Days Counter is a paid API for AI agents from darwin-business-calendar.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Counts the number of business days between two ISO dates, excluding weekends and country-specific public holidays.

## Facts

- Endpoint: GET https://darwin-business-calendar.onrender.com/business-days
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/darwin-business-calendar-business-days-counter-62a27805
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_59UKPsipnZp5TUix7bsdc

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 darwin-business-calendar-business-days-counter-62a27805
```

Example prompt: How many business days are there between January 15, 2025 and March 31, 2025 in Brazil, excluding weekends and public holidays?

## When to prefer this

Choose this endpoint when you need a lightweight, low-cost API to compute exact business-day counts between two dates with country-specific holiday exclusions — particularly for Brazil (BR default). Ideal for contract, HR, invoicing, or project scheduling workflows where weekends and local holidays must be excluded. Prefer this over manual date arithmetic or generic calendar libraries when holiday accuracy for a specific country is required.

## Known failure modes

- Missing required 'start' or 'end' query parameter returns an error
- Malformed date format (not YYYY-MM-DD) causes a parsing error
- Invalid or unsupported country code may fall back to default (BR) or return an error
- End date before start date may return zero or an error
- Render.com cold-start latency on first request after inactivity

## How this service works

Count business days between two ISO dates, excluding weekends and public holidays.

## Output

Returns a JSON object containing the country code, start date, end date, total number of business days in the range (as an integer), and an array of excluded public holiday dates 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": "Inclusive end date in YYYY-MM-DD format"
      },
      "start": {
       "type": "string",
       "description": "Inclusive start date in YYYY-MM-DD format"
      },
      "country": {
       "type": "string",
       "default": "BR",
       "description": "ISO 3166-1 alpha-2 country code"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "country",
      "start",
      "end",
      "businessDays",
      "excludedHolidays"
     ],
     "properties": {
      "end": {
       "type": "string"
      },
      "start": {
       "type": "string"
      },
      "country": {
       "type": "string"
      },
      "businessDays": {
       "type": "integer"
      },
      "excludedHolidays": {
       "type": "array",
       "items": {
        "type": "string"
       }
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/darwin-business-calendar-business-days-counter-62a27805/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from darwin-business-calendar.onrender.com](https://www.zero.xyz/host/darwin-business-calendar.onrender.com/llms.txt)