Why Checking If a Bank Is Open Today Is a Hard Software Engineering Problem

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A software developer has outlined the hidden complexity behind answering a simple question: whether a bank is open on any given day. Beyond weekends, the challenge involves handling public holidays, observed substitute dates, and branch-specific rules that vary by institution. Time zones add another layer of difficulty, since a user's local date may differ from the date at the bank's physical location. The developer proposes a layered architecture separating calendar logic, holiday data, institution rules, and a status engine to manage these variables cleanly. The system also advocates for richer status responses that explain why a bank is closed, rather than returning a plain open or closed value.

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