# ISO Week Date & Calendar Decomposition API

> ISO Week Date & Calendar Decomposition API is a paid API for AI agents from api.24klabs.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Converts a date into ISO 8601 week-date components (year, week number, weekday), plus ordinal day-of-year, quarter, and days remaining in the year.

## Facts

- Endpoint: POST https://api.24klabs.ai/api/iso-week-date
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/iso-week-date-calendar-decomposition-api-b02e6aa7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lxs9mMqedh85qDz9rMxJa

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 iso-week-date-calendar-decomposition-api-b02e6aa7 -d '<json body>'
```

Example prompt: What is the ISO week number, weekday, quarter, ordinal day of year, and days remaining in 2025 for March 15, 2025?

## When to prefer this

Choose this endpoint when you need precise ISO 8601 week-date decomposition alongside ordinal and quarter data in a single call, especially for scheduling, sprint planning, reporting pipelines, or calendar-based logic that requires week numbers — rather than building this logic manually or using a generic date library.

## Known failure modes

- Invalid or unparseable date string returns an error response
- Ambiguous date formats (e.g. 01/02/03) may be rejected or misinterpreted
- Missing date field in POST body returns a validation error
- Dates outside supported range may return an error

## How this service works

Convert a date to its ISO 8601 week-date (year, week number, weekday), ordinal day-of-year, quarter, and days remaining in the year.

## Output

Returns the ISO 8601 week-date components: ISO week-year (which may differ from the calendar year near year boundaries), ISO week number (1–53), ISO weekday number (1=Monday, 7=Sunday), the ordinal day-of-year (1–366), the calendar quarter (1–4), and the number of days remaining in the year.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "date": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "iso_week": 31,
  "iso_year": 2026,
  "iso_weekday": 1
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/iso-week-date-calendar-decomposition-api-b02e6aa7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.24klabs.ai](https://www.zero.xyz/host/api.24klabs.ai/llms.txt)