For date and time calculations in voice agent, how are people solving it are they using a tool or doing the calculation in the prompt itself?

Thanks for reaching out, Shriniket. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.

Is it a function call or a tool call? which is faster and easier to implement?

You're asking whether to use a "function call" or a "tool call" for date/time work and which is faster/easier. Short answer: • Use a tool exposed as a function (i.e., a function decorated as a tool). From the agent's perspective the LLM invokes a tool via a function call — practically the same flow — but implementing it as a tool is the recommended, simplest approach. Why: • A tool implemented as a

function_tool

lets you write real code (timezone-aware

datetime

, parsing libraries) and expose it cleanly to the agent. • It's easier to test, maintain, and reason about than embedding logic in the prompt. • Performance: calling a local function/tool is fast; any overhead is minimal and typically lower than trying to rely on repeated LLM reasoning or on external HTTP services. Recommendation: • Implement a small tool (function) that: ◦ Parses relative terms ("tomorrow", "next Friday") ◦ Applies timezone/locale ◦ Returns ISO timestamps or structured fields • This is the fastest to implement and most reliable in production. If you want, I can provide a short Python or Node example of such a tool and the minimal prompt glue to call it. Which language do you prefer?