Timezone Truth for ChatGPT

com.gumballtools/timezone-truth

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

client:ChatGPT transport:streamable-http tools:1

Install Timezone Truth in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://timezone-truth.gumballtools.com/api/mcp

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs