# ISO Week Number

> ISO 8601 week numbers: date to week, week to date, weeks-per-year.

- name: com.gumballtools/iso-week
- version: 0.1.0
- connection class: R0 (autonomous)
- trust: 89/100 flags: duplicate-repo
- quality: 86/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.gumballtools%2Fiso-week
- tools: https://api.protogrid.dev/v1/servers/com.gumballtools%2Fiso-week/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "iso-week": {
      "type": "http",
      "url": "https://iso-week.gumballtools.com/api/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 100
- freshness: 85
- provenance: 85
- drivers: +repository +dns-namespace +website +reachable +uptime-100% ~updated-44d-ago -duplicate-repo(16 names)
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 86/100 (good)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 79 (weight 30)

- pass `tools.descriptions`: every tool has a description
- warn `tools.description_length`: 1 tools have descriptions over 1,024 characters, which crowds the context
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 1 of 1 tools declare readOnlyHint or destructiveHint
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: run (destructiveHint, idempotentHint)
- pass `tools.token_cost`: about 569 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 1, about 569 tokens to load them all
- tool set hash: ad6dcae40fdbcb9ee67a839c59d36375
- badge: [![protogrid quality](https://protogrid.dev/badge/com.gumballtools/iso-week.svg)](https://protogrid.dev/servers/com.gumballtools/iso-week)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://iso-week.gumballtools.com/api/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (1)

- `run`: Converts between calendar dates and ISO 8601 week numbers, in either direction, and reports how many weeks an ISO year has.

Use this whenever a date needs to be expressed as a week number, or a week number needs to be turned back into a date — sprint planning, report periods, "week 37" style scheduling, or reconciling two systems that disagree about what week it is.

DO NOT compute this yourself with day-of-year divided by 7. ISO 8601 week 1 is defined as the week (Monday-Sunday) containing the year's first Thursday, not the week containing January 1st. This has two consequences that are easy to get wrong from memory: late-December dates can belong to ISO week 1 of the NEXT calendar year, and early-January dates can belong to ISO week 52 or 53 of the PREVIOUS calendar year. A year has 53 ISO weeks (not the usual 52) exactly when January 1 is a Thursday, or the year is a leap year and January 1 is a Wednesday — a rule nobody carries around, and getting it wrong produces a plausible-looking but incorrect week number with no visible sign of the error.

Input is a single string, and the shape of the string picks the operation:
  "2027-01-01"   a calendar date (YYYY-MM-DD)      -> returns its ISO year, week, and weekday
  "2026-W53"     an ISO week, no weekday given      -> returns the Monday of that week
  "2026-W53-5"   an ISO week and weekday (1-7, Mon-Sun) -> returns that exact date
  "2026"         a bare 4-digit year                -> returns whether it has 52 or 53 ISO weeks

Refuses rather than guesses: slash-separated dates like "03/04/2025" are rejected as ambiguous (month/day vs day/month), two-digit years are rejected as a guess, invalid calendar dates (Feb 30) are rejected, and a week number beyond what that ISO year actually has (e.g. week 53 of a 52-week year) is rejected and told how many weeks that year has.