What is the mail date string format (rfc2822)

About

A date can be represented as a string with the date format defined in a email (ie rfc2822 format).

This format is the second most popular format below ISO 8601 format and is well spread.

For instance, this format is recognized by google (Ref) but they prefers the ISO 8601 format.

Articles Related

Example

Thu, 21 Dec 2000 16:01:07 +0200

Syntax

Space are recommended but not mandatory.

• railroad

(* Day name *)
[[  "Mon" | "Tue" | "Wed" | "Thu" | "Fri" | "Sat" | "Sun" ] ","]
(* Day digit *)
'day (2 digit)'
(* Month Short Name *)
( "Jan" | "Feb" | "Mar" | "Apr" | "May" | "Jun" | "Jul" | "Aug" |  "Sep" | "Oct" | "Nov" | "Dec" )
(* Year *)
'year (4 digits)'
(* Time *)
'hour (2 digits)' ":" 'minute (2 digits)' [ ":" 'second (2 digit)' ]
(* Zone *)
( "+" | "-" ) 'zone (4 digit)'

Library

• Php: the r format. Example:

gmdate('r', $timestamp)

Documentation / Reference

• rfc2822 format (specifically the section 3.3)
• IETF RFC 850
• RFC822 - internet text messages (arpa) - chapter 5 (Date and time specification)