parseRfc2822

Signature

parseRfc2822(value: string): string

import { parseRfc2822 } from "@northguild/gmt/zoned/parse";

Parse an RFC 5322 (RFC 2822) date-time string — the fixed grammar email

• Date: headers use — into a zoned ISO 8601 datetime string.
• Decoding, not display. Accepts English weekday/month abbreviations only, per the fixed grammar (see formatRfc2822’s JSDoc and roadmap Decision 1).
• Accepts a leading day-of-week (not cross-validated against the computed date, the same deliberate scope limit parseDateTimeWithPattern/J11 uses for its EEEE/EEE tokens) and an optional :ss seconds field.
• Accepts a 1- or 2-digit day (the formal grammar’s 1*2DIGIT), unlike parseHttp/parseSql, which both require exactly 2 digits.
• Accepts a numeric +HHMM/-HHMM offset or one of RFC 5322’s obsolete named zones (GMT, UT, and the eight North American zones); any other obs-zone letter is unrecognized and rejected.
• The resulting offset becomes the zoned string’s time zone identifier (e.g. -05:00), since RFC 2822 carries no IANA zone name to recover.

Parameters

Parameter	Type	Description
value	string	RFC 5322 date-time string (e.g. “Fri, 15 Mar 2024 14:30:00 -0400”)

Returns

zoned ISO 8601 datetime string, or “” on invalid input

Examples

parseRfc2822("Fri, 15 Mar 2024 14:30:00 -0400") // "2024-03-15T14:30:00-04:00[-04:00]"
parseRfc2822("5 Jan 2024 09:00:00 GMT") // "2024-01-05T09:00:00+00:00[+00:00]"
parseRfc2822("not a date") // ""

Source

zoned/parse/parseRfc2822.ts