# Japan Business Day API – Payment Due Date Calculator

> Japan Business Day API – Payment Due Date Calculator is a paid API for AI agents from japan-business-day-api.matchan962.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).

Calculates Japanese payment due dates based on shimebi (closing day) and shiharaibi (payment day) conventions, adjusting for weekends and Japanese holidays.

## Facts

- Endpoint: GET https://japan-business-day-api.matchan962.workers.dev/v1/payment-due-date?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/japan-business-day-api-payment-due-date-calculator-b308582d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JLKPfKjrg1UFnSAw23ugx

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 japan-business-day-api-payment-due-date-calculator-b308582d
```

Example prompt: For an invoice dated November 15, 2024, with a month-end closing and payment due at the end of the following month, what is the actual payment due date in Japan — using the bank calendar and shifting to the next business day if it falls on a holiday?

## When to prefer this

Use this endpoint when you need to compute Japanese B2B payment due dates respecting shimebi/shiharaibi conventions and Japanese public or bank holidays. It is purpose-built for Japanese accounts payable workflows, ERP integrations, and billing systems that must handle holiday-shifted due dates — superior to generic date arithmetic or non-Japan-aware business day calculators.

## Known failure modes

- Missing required query parameters (date, closing, payDay) returns a 400 error
- Invalid date format returns a parsing error
- Month offset outside 0-3 range is rejected
- Unsupported adjust or calendar enum values return a validation error
- Network or worker downtime returns a 5xx error

## How this service works

Japanese payment terms calculator (shimebi/shiharaibi): e.g. 'month-end close, paid end of next month', shifted to the previous/next business day when the due date is a weekend or Japanese holiday. Supports bank calendar (Dec 31 - Jan 3).

## Output

Returns the calculated payment due date as a date, adjusted for weekends and Japanese holidays (national or bank calendar) according to the specified closing day, payment day, and month offset.

## 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",
      "closing",
      "payDay"
     ],
     "properties": {
      "date": {
       "type": "string",
       "format": "date",
       "description": "Transaction or invoice date"
      },
      "adjust": {
       "enum": [
        "previous",
        "next",
        "none"
       ],
       "type": "string"
      },
      "payDay": {
       "type": "string",
       "description": "Payment day of month: 1-31 or 'end'"
      },
      "closing": {
       "type": "string",
       "description": "Closing day of month: 1-31 or 'end'"
      },
      "calendar": {
       "enum": [
        "national",
        "bank"
       ],
       "type": "string",
       "description": "national = weekends + Japanese national holidays; bank = also Dec 31 - Jan 3 (bank holidays)"
      },
      "monthOffset": {
       "type": "integer",
       "maximum": 3,
       "minimum": 0,
       "description": "Months after closing (1 = next month)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/japan-business-day-api-payment-due-date-calculator-b308582d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from japan-business-day-api.matchan962.workers.dev](https://www.zero.xyz/host/japan-business-day-api.matchan962.workers.dev/llms.txt)