ISO week numbers

Convert a date to its ISO 8601 week (year, week, weekday) with the Monday and Sunday of that week, or a week to its dates.

CHF 0.001 / callCall it Try it

Bond marine chronometerca. 1812

Details

Rules: weeks start on Monday; week 1 contains the first Thursday of the year; some years have 53 weeks.

Price: CHF 0.001 per call (first 100 calls per day free).

Example: {"date":"2027-01-01"} → {"iso":"2026-W53-5","monday":"2026-12-28","sunday":"2027-01-03"}.

Call it

REST

curl -X POST https://api.tausendwerk.xyz/v1/iso-week \
  -H "Content-Type: application/json" \
  -d '{"date":"2027-01-01"}'

MCP tool name

iso_week

After the free 100 calls per day, add a key: Authorization: Bearer tw_live_…. Pricing

Try it

Runs against the live API with the free allowance.

Input (JSON)

Input schema JSON Schema

{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "date": {
      "type": "string",
      "format": "date"
    },
    "year": {
      "type": "integer",
      "minimum": 1,
      "maximum": 9999
    },
    "week": {
      "type": "integer",
      "minimum": 1,
      "maximum": 53
    }
  },
  "examples": [
    {
      "date": "2027-01-01"
    }
  ]
}

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