# Halowerk Calendar & Workdays API

> Halowerk Calendar & Workdays API is a paid API for AI agents from tools.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns public holiday lists by German/Austrian/Swiss federal state, checks if a date is a workday, calculates workdays between two dates, adds workdays to a date, and returns timezone offsets including DST.

## Facts

- Endpoint: POST https://tools.halowerk.com/v1/calendar/workdays
- 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/halowerk-calendar-workdays-api-acc62b1d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iRs3il51xHPnuXP4w_NLq

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 halowerk-calendar-workdays-api-acc62b1d -d '<json body>'
```

Example prompt: Is March 19 next year a workday in Bavaria (Germany), and if not, how many workdays are there between March 15 and March 25 in that state?

## When to prefer this

Choose this endpoint when you need DACH-region (Germany, Austria, Switzerland) specific public holiday data at the federal-state (Bundesland/Kanton) level, or when you need to calculate business days, add workdays to a date, or get DST-aware timezone offsets for these countries. It is more precise than generic global calendar APIs because it has granular Bundesland-level holiday data for all three countries.

## Known failure modes

- Invalid or unsupported country code returns an error
- Unsupported Bundesland/canton identifier causes validation failure
- Date format mismatch leads to parsing error
- Future years beyond available holiday data may return incomplete results
- Missing required fields in POST body returns 400 Bad Request

## How this service works

Feiertagsliste je Bundesland für DE, AT und CH, Werktagsprüfung, Werktage zwischen zwei Daten, Werktage addieren und Zeitzonen-Offset inklusive Sommerzeit.

## Output

Returns structured data including: public holiday lists with names and dates for the requested state/country, a boolean workday flag for a specific date, the count of workdays between two dates, a resulting date after adding N workdays, and/or a timezone offset value in hours/minutes including DST correction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string"
  },
  "date": {
   "type": "string",
   "description": "ISO-Datum für Werktagsprüfung"
  },
  "from": {
   "type": "string"
  },
  "year": {
   "type": "integer"
  },
  "region": {
   "type": "string",
   "description": "Bundeslandkürzel, z. B. NW, BY, SN"
  },
  "country": {
   "enum": [
    "DE",
    "AT",
    "CH"
   ],
   "type": "string",
   "default": "DE"
  },
  "timezone": {
   "type": "string",
   "default": "Europe/Berlin"
  },
  "add_workdays": {
   "type": "integer",
   "description": "Werktage auf date addieren"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-calendar-workdays-api-acc62b1d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tools.halowerk.com](https://www.zero.xyz/host/tools.halowerk.com/llms.txt)