AI Agents Should Call Tools for Time: Building Nepali Temporal Infrastructure with FastAPI and Swiss Ephemeris A Claude, GPT, Gemini, or Cursor agent receives a simple task. Check whether a date falls inside a valid reporting period. The date uses Bikram Sambat, the official calendar used across Nepal. The agent answers confidently. The output passes the application schema. The log shows a successful run. The downstream system accepts the result. The date is wrong. That is the failure mode that pushed me deeper into Project Parva. Date bugs already create enough damage in normal software. Date bugs inside agentic systems feel worse because the model can wrap a wrong answer in fluent reasoning, structured JSON, and an explanation that sounds operationally correct. Project Parva is my attempt to build the grounding layer that Nepali time deserves. It started as an open-source Nepali calendar API.…