Reference

Reference: Working days

Working days between two dates by state, without weekends and public holidays.

Counts the working days (Arbeitstage) between two dates in a federal state: Monday to Friday, or Monday to Saturday if you choose, minus the statutory public holidays. For partial months, day rates, deadlines and workforce planning.

Endpoints and calls

Access	Call
REST API	`GET /hr/arbeitstage`
SDK JavaScript	`qk.hr.arbeitstage(…)`
SDK Python	`qk.hr.arbeitstage(…)`
CLI	`qk arbeitstage --von 2027-01-01 --bis 2027-01-31 --land HE`
MCP tool	`hr_arbeitstage`

Parameters

Name	Type	Required	Default	Allowed	Description
`von`	date (YYYY-MM-DD)	yes			First day, inclusive
`bis`	date (YYYY-MM-DD)	yes			Last day, inclusive. Not before von, a period of at most ten years, within 2015 to 2035
`land`	text	yes		BW, BY, BE, BB, HB, HH, HE, MV, NI, NW, RP, SL, SN, ST, SH, TH	State code, for example HE; the name such as Hessen also works
`samstag`	true or false	no	false		Count Saturdays as working days (Werktage). Default: false
`regionale`	true or false	no	false		Subtract regional holidays. Default: false

The API rejects unknown parameters with unbekannter_parameter. In addition there are format and trennzeichen, see CSV.

Response fields

Field	Type	Meaning
`datensatz`	Text	Dataset id
`von`	Date	First day, inclusive
`bis`	Date	Last day, inclusive
`land`	Text or null	State code
`land_name`	Text	Name of the state
`samstag_als_arbeitstag`	Boolean	Whether Saturdays are counted
`regionale_feiertage_abgezogen`	Boolean	Whether regional holidays are subtracted
`kalendertage`	Integer	Number of calendar days
`arbeitstage`	Integer	Number of working days
`feiertage_an_arbeitstagen`	List	Public holidays subtracted
`rechtsgrundlage`	Text	Law or ordinance
`quelle`	Object	Title and URL of the source the value is based on
`quellen`	List	All legal provisions the response is based on, with title and URL
`hinweise`	List	Limits of the values or the calculation, in sentences
`stand`	Date	Date of the last check against the source
`lizenz`	Text	Terms of use for the values
`zitat`	Text	Ready-made sentence for citing, with value, validity, legal basis and source
`datenstand`	Text	Id of the data snapshot: date and sequence number of the last changelog entry (/v1/aenderungen) affecting this dataset. The same datenstand means unchanged content, useful for auditors and for comparing two requests

Example

Call with von = 2027-01-01, bis = 2027-01-31, land = HE. The response is generated by the same code that answers the API.

api.quellenkontor.dev/v1/hr/arbeitstage?von=2027-01-01&bis=2027-01-31&land=HE

Zur API-Doku →

curl "https://api.quellenkontor.dev/v1/hr/arbeitstage?von=2027-01-01&bis=2027-01-31&land=HE" \
  -H "Authorization: Bearer $QK_KEY"

import { Quellenkontor } from "@quellenkontor/sdk";

const qk = new Quellenkontor(process.env.QK_KEY);
const daten = await qk.hr.arbeitstage({ von: "2027-01-01", bis: "2027-01-31", land: "HE" });

import os
from quellenkontor import Quellenkontor

qk = Quellenkontor(api_key=os.environ["QK_KEY"])
daten = qk.hr.arbeitstage(von="2027-01-01", bis="2027-01-31", land="HE")

$ qk arbeitstage --von 2027-01-01 --bis 2027-01-31 --land HE

{
  "name": "hr_arbeitstage",
  "arguments": {
    "von": "2027-01-01",
    "bis": "2027-01-31",
    "land": "HE"
  }
}

This is how an agent calls the tool. Server setup is described in the MCP docs.

Antwort200 OK · JSON

{
  "datensatz": "arbeitstage",
  "von": "2027-01-01",
  "bis": "2027-01-31",
  "land": "HE",
  "land_name": "Hessen",
  "samstag_als_arbeitstag": false,
  "regionale_feiertage_abgezogen": false,
  "kalendertage": 31,
  "arbeitstage": 20,
  "feiertage_an_arbeitstagen": [
    {
      "datum": "2027-01-01",
      "name": "Neujahr",
      "regional": false
    }
  ],
  "rechtsgrundlage": "Hessisches Feiertagsgesetz (HFeiertagsG), Hessen",
  "quelle": {
    "titel": "Hessisches Feiertagsgesetz (HFeiertagsG), Hessen",
    "url": "https://www.rv.hessenrecht.hessen.de/bshe/document/jlr-FeiertGHE1952pP1"
  },
  "quellen": [
    {
      "titel": "Hessisches Feiertagsgesetz (HFeiertagsG), Hessen",
      "url": "https://www.rv.hessenrecht.hessen.de/bshe/document/jlr-FeiertGHE1952pP1"
    }
  ],
  "hinweise": [
    "Gezählt werden Montag bis Freitag.",
    "Regionale Feiertage sind nicht abgezogen. Setze regionale=true, wenn dein Standort in einem Gebiet mit regionalem Feiertag liegt."
  ],
  "stand": "2026-09-23",
  "lizenz": "Berechnung nach den genannten Normen. Nutzung nach den Nutzungsbedingungen von Quellenkontor.",
  "zitat": "Arbeitstage vom 01.01.2027 bis 31.01.2027 in Hessen: 20 von 31 Kalendertagen, Montag bis Freitag ohne gesetzliche Feiertage des Landes. Rechtsgrundlage: Hessisches Feiertagsgesetz (HFeiertagsG), Hessen. Quelle: Hessisches Feiertagsgesetz (HFeiertagsG), Hessen, https://www.rv.hessenrecht.hessen.de/bshe/document/jlr-FeiertGHE1952pP1. Daten: Quellenkontor (quellenkontor.dev).",
  "datenstand": "2026-09-23.1"
}

Error cases

Status	Code	When
400	`parameter_fehlt`	if von or bis or land is missing
400	`ungueltiger_parameter`	wrong format or a value outside: land (BW, BY, BE, BB, HB, HH, HE, MV, NI, NW, RP, SL, SN, ST, SH, TH)
400	`unbekannter_parameter`	a parameter this dataset does not have
404	`kein_wert`	outside the coverage (2015 to 2035) or the value for this period has not been promulgated yet
401, 429	see errors	all error codes

Schema for MCP

This is how the MCP server describes the arguments of the tool hr_arbeitstage:

inputSchema

{
  "type": "object",
  "properties": {
    "von": {
      "description": "Erster Tag, einschließlich",
      "type": "string",
      "format": "date",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "examples": [
        "2027-01-01"
      ]
    },
    "bis": {
      "description": "Letzter Tag, einschließlich. Nicht vor von, Zeitraum höchstens zehn Jahre, innerhalb 2015 bis 2035",
      "type": "string",
      "format": "date",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "examples": [
        "2027-01-31"
      ]
    },
    "land": {
      "description": "Kürzel des Bundeslands, zum Beispiel HE; der Name wie Hessen geht auch",
      "type": "string",
      "enum": [
        "BW",
        "BY",
        "BE",
        "BB",
        "HB",
        "HH",
        "HE",
        "MV",
        "NI",
        "NW",
        "RP",
        "SL",
        "SN",
        "ST",
        "SH",
        "TH"
      ],
      "examples": [
        "HE"
      ]
    },
    "samstag": {
      "description": "Samstage mitzählen (Werktage). Standard: false",
      "type": "boolean"
    },
    "regionale": {
      "description": "Regionale Feiertage abziehen. Standard: false",
      "type": "boolean"
    }
  },
  "required": [
    "von",
    "bis",
    "land"
  ],
  "additionalProperties": false
}

Source and freshness

Item	Content
Source	Public holiday laws of the federal states (Feiertagsgesetze der Länder)
License	Calculation under the cited provisions. Use under the Quellenkontor terms of use.
Updates	when the law changes
Coverage	Germany, 2015 to 2035
Last checked	September 23, 2026
Next expected change	follows the public holidays

Overview with tables and questions about the dataset: Working days calculator. Report an error through the contact form.

Something missing or unclear? Write to us and we will extend the docs.