openworkdays for ChatGPT

io.github.solvohq/openworkdays

Zero-signup business-day date-math API: add days, count days between dates, is-business-day.

client:ChatGPT transport:streamable-http tools:1

Install openworkdays in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://openworkdays.vercel.app/api/mcp

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