# Timezone Truth

> Convert times between IANA zones and detect skipped or ambiguous DST local times.

- name: com.gumballtools/timezone-truth
- 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%2Ftimezone-truth
- tools: https://api.protogrid.dev/v1/servers/com.gumballtools%2Ftimezone-truth/tools

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

## Connection (mcpServers)

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


## Trust

- hygiene: 80
- liveness: 100
- freshness: 85
- provenance: 85
- drivers: +repository +dns-namespace +website +reachable +uptime-100% ~updated-45d-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: convert_time (destructiveHint, idempotentHint)
- pass `tools.token_cost`: about 645 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 645 tokens to load them all
- tool set hash: 6dc5bee5a492eb06938afceb439d0baa
- badge: [![protogrid quality](https://protogrid.dev/badge/com.gumballtools/timezone-truth.svg)](https://protogrid.dev/servers/com.gumballtools/timezone-truth)
- 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://timezone-truth.gumballtools.com/api/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (1)

- `convert_time`: Convert a wall-clock time between two IANA timezones, and report the ways the conversion can be wrong.

ALWAYS use this instead of doing the arithmetic. Timezone conversion looks like addition and is not: the mapping from a local time to an instant is not a function.

- On the spring-forward date, an hour of local time DOES NOT EXIST. Asked to convert 02:30 on that date, a model will return a plausible timestamp for a time that never happens. This tool returns null and says why.
- On the fall-back date, an hour happens TWICE. There are two correct answers an hour apart; this returns both rather than silently choosing.
- The gap between two zones is not constant. Zones start and end daylight saving on different dates, so a cached offset is wrong for weeks each year.
- Not all offsets are whole hours: India is +05:30, Nepal +05:45.

Input: `time` must be YYYY-MM-DD HH:MM (or with T, and optional seconds) — free-form dates are refused rather than guessed. `from` and `to` must be full IANA names such as "America/New_York".

ABBREVIATIONS ARE REJECTED, deliberately, even though most runtimes accept them. Node resolves "BST" to Bangladesh Standard Time (UTC+06:00) when nearly everyone writing it means British Summer Time (UTC+01:00) — a five-hour error that yields a perfectly plausible timestamp. Same for CST, IST, PST, and EST.

Returns: the chosen UTC instant (null if the local time does not exist), every candidate instant, both zone readings with the offset and abbreviation that applied on THAT date, the difference between the zones, upcoming clock changes for both, and warnings. Check `warnings` for severity "error" before using the result.