How do you make a piece of code reusable so that it can run for any year, for example 2026, even if you don't have data for all 12 months?

To make code reusable across years, parameterize the year and any date ranges instead of hard‑coding them. Pass the target year as a function argument or read it from a configuration file. Use date‑arithmetic functions (e.g., DATE_TRUNC, DATE_ADD, or a library like pandas in Python) to generate the start and end dates for the year. If data for some months is missing, guard against it by checking for nulls or empty results and handling them gracefully (e.g., skip the month, fill with zeros, or log a warning). This approach keeps the logic generic: the same code can be called with 2023, 2024, 2026, etc., and it will adapt to the available data without manual changes.