Date Math for ChatGPT

io.github.jowendelapena/date-math

Date/time math for agents: business days, holidays, time zones, cron, RRULE. 25 free calls/day.

client:ChatGPT transport:streamable-http runtime:npm tools:13

Install Date Math in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://date-math.datemath.workers.dev/mcp

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