EpochLab

RFC3339 Converter

Convert a date to RFC 3339

The internet's profile of ISO 8601 — what JSON APIs, logs and every timestamp field in an RFC actually mean — with the differences from plain ISO spelled out.

Questions people ask

The things that come up about rfc3339 converters, answered plainly.

How is RFC 3339 different from ISO 8601?

It is a narrower profile. RFC 3339 requires a full date and time with an offset, forbids the basic form without separators, and permits a lowercase t and z and a space instead of T. Every RFC 3339 timestamp is valid ISO 8601; the reverse is not true — 2024-W29-2 is ISO but not RFC 3339.

What does -00:00 mean?

In RFC 3339 it means the offset is unknown, as distinct from Z, which means the time is genuinely UTC. It is a real distinction and almost universally ignored.

Related tools

Render an instant in any pattern or locale, and read one back out of text.

ISO Date ConverterThe extended form, the basic form, the week date and the ordinal date — all four ISO 8601 shapes for one instant, plus a parser for reading them back.
RFC2822 ConverterThe email and HTTP form — `Tue, 16 Jul 2024 16:00:00 +0000` — with the HTTP variant beside it, which is the same idea with different rules.
Date FormatterOne date, every common output at once — ISO, RFC, SQL, filename-safe, spoken English — plus a pattern field for anything the list does not cover.
ISO 8601 ValidatorA strict check against the standard, with the specific rule any failure broke — and a note on whether it would also pass as RFC 3339, which is stricter still.

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