Timezone Truth

com.gumballtools/timezone-truthVersion 0.1.0

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

Status

Responds850 msNov 14, 2026, 14:00 UTCAnswered our handshake without sign-in.

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Last checked: Nov 14, 2026, 14:00 UTC
Latency: 850 ms
Remotes responding: 1 of 1
Sign-in: No sign-in
Hosting: Hosted outside the EU (detected)
Registry data as of: Nov 14, 2026, 22:14 UTC

Data from the official MCP Registry, checked by run.zero. How we check

Connect

Streamable HTTP

https://timezone-truth.gumballtools.com/api/mcpResponds850 msNov 14, 2026, 14:00 UTC

No sign-in

Claude Code

claude mcp add --transport http timezone-truth https://timezone-truth.gumballtools.com/api/mcp

Claude Desktop and claude.ai

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Settings > Connectors > Add custom connector
Name: timezone-truth
Remote MCP server URL: https://timezone-truth.gumballtools.com/api/mcp

Cursor

{
  "mcpServers": {
    "timezone-truth": {
      "url": "https://timezone-truth.gumballtools.com/api/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"timezone-truth","type":"http","url":"https://timezone-truth.gumballtools.com/api/mcp"}'

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Tools

1 tools

Tools of Timezone Truth
	Description		Read-only	Idempotent	Open world
`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.	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.	Not declared	Yes	Not declared	No

Details

Registry status: Active
Published: Sep 5, 2026
Updated: Sep 5, 2026
Website: https://timezone-truth.gumballtools.com/⁠ (opens in a new tab)
Repository: https://github.com/bwalvoord/gumball⁠ (opens in a new tab)
Categories: Uncategorized
GDPR: Not declared

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