# Deadline Decoder

> Find every deadline, required action and consequence in a letter or notice. Paste or upload an official letter, invoice, reminder or notice (English or German). Deadline Decoder extracts absolute dates and relative deadlines such as "within 14 days" or "binnen eines Monats", resolves them against the letter or receipt date, lists what you must do and what happens otherwise, and exports the deadlines as a calendar (.ics) file.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://deadlinedecoder.usefulweb.site/ (interactive tool at https://deadlinedecoder.usefulweb.site/tool)
- JSON API: POST https://deadlinedecoder.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://deadlinedecoder.usefulweb.site/api/v1/tool)
- OpenAPI: https://deadlinedecoder.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://deadlinedecoder.usefulweb.site/mcp - tool `deadline_decoder`

## Inputs
- text (textarea): Letter or notice text - Paste the text here, or use one of the other options below (exactly one).
- file (file): Or upload a file - TXT, PDF, DOCX, HTML or a photo/scan (PNG/JPG, read with OCR). Max 5 MiB.
- referenceDate (date): Reference date - Date of the letter or the day you received it. Relative deadlines ("within 14 days") are counted from here. Defaults to today.
- referenceType (select): The reference date is…
- dateOrder (select): Numeric dates like 03/04/2026 are

## Method
- The text is split into sentences (paragraph-, bullet- and abbreviation-aware; German ordinal dates like "12. Oktober" are not treated as sentence ends).
- Absolute dates are matched in the formats 2026-10-12, 12.10.2026, 12/10/2026 (day/month or month/day as selected; an unambiguous day > 12 overrides), "October 12, 2026", "12 Oct 2026" and "12. Oktober 2026". Impossible dates (31.02.) are discarded.
- A date counts as a deadline when its sentence contains a deadline cue (by, until, no later than, due, bis, spätestens, fällig, Frist …) or a required-action pattern; other dates are listed as "mentioned".
- Relative deadlines ("within 14 days", "no later than 30 days after receipt", "innerhalb von 2 Wochen", "binnen eines Monats") are added to the reference date: days and weeks as calendar days, business days skip Saturdays and Sundays (public holidays are not considered), months/years as calendar months (clamped to the month end).
- Required actions are sentences matching modal or request patterns (must, shall, required, please pay/submit, bitte, müssen, "ist … zu zahlen", "überweisen Sie" …). Consequences are sentences with otherwise/failure-to/fee/penalty/escalation patterns (andernfalls, sonst, Mahngebühr, Säumniszuschlag, Inkasso, Vollstreckung …).
- Every finding quotes the exact sentence and names the rule that fired. Confidence is "pattern-match": nothing is guessed by an AI model.

## Limits
- Not legal advice. Rule-based extraction can miss deadlines or misread dates, and legal deadline rules (e.g. when a letter counts as received, weekends and public holidays) differ by country and authority. Always check the original document and, if in doubt, ask the sender or an adviser.