API Design · Middle · Question 55 of 75

How should an API handle time zones in inputs and outputs?

1Return times as local strings for each country
✓Correct answer: Store and return timestamps in UTC with an offset (Z), and accept the user's time zone separately when local dates matter
3Use the server's local time without offsets

Explanation

Calendar-style data (birthdays, opening hours) may need dates without times or explicit IANA zones like Europe/Kyiv.

Further reading

RFC 3339: Date and time on the Internet ↗

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