Decoding Real-World JSON

Dates: the classic networking pain

JSON has no date type. None. It has strings, numbers, booleans, arrays, and objects — so every backend on Earth ships dates as strings, like "2026-07-01T15:00:00Z". That format is called ISO-8601: year-month-day, a T, the time, and a timezone (Z means UTC, "universal time").

Swift's Date type, on the other hand, is a real point in time you can compare and format. Somebody has to bridge the two — and that somebody is JSONDecoder, via its dateDecodingStrategy property. Set it once and every Date field in every struct decodes automatically.