calculate_trip_per_diem
ChatGPTUse this when the user wants a per diem total or a day-by-day table for travel dates: "GSA per diem total for Denver Nov 10-13, lunch provided on the 11th", "per diem for Huntsville AL then Atlanta, 3 nights each, first and last day are travel days", "per diem calculator", "voucher day-by-day table", a TDY or business trip budget, an expense report or a grant budget, with one destination or several legs (US CONUS, Alaska, Hawaii and US territories, or foreign/OCONUS cities). Applies the Federal Travel Regulation (the JTR uses the same 75% travel-day rule) to the official rates for each night: lodging capped at that night's rate by month and fiscal year (seasonal and 1 October FY2027 changes handled), nights = days - 1 (no lodging on the return day), M&IE at 75% on the first and last day and 100% on full days, M&IE by where the traveler sleeps, provided meals (government or conference registration, e.g. "lunch provided") deducted at the official breakfast/lunch/dinner amounts, and actual room costs capped at the rate. Returns a dated row per day (location, lodging, M&IE %, deductions, day total), the trip total and a CSV for the voucher. If one leg cannot be priced, the other legs are still totalled and that leg is flagged with what is missing. Pass ZIP or city + state for US places, country + city abroad (country optional for well-known cities). Do not use for a single rate question (use lookup_per_diem_rate), mileage or airfare, how to file a voucher in Concur or DTS, or to decide what an employer will actually reimburse. Not affiliated with GSA.
