Sorry guys, this was supposed to go to the JavaMail mailing list. Sorry. -----Original Message----- From: Donie Kelly [mailto:[EMAIL PROTECTED] Sent: 20 January 2004 12:15 To: Tomcat Users List (E-mail) Subject: rfc2822 clarification on date headers Hi all Javamail generates a date in the format: Date: Tue, 20 Jan 2004 11:57:37 +0000 (GMT) The spec below implies that the timezone is either a numeric offset or the timezone is specified like Date: Fri, 23 Jan 2004 11:57:24 GMT Can somebody clarify why javamail uses both forms? Extract from rfc2822 below Thanks Donie 3.3. Date and Time Specification Date and time occur in several header fields. This section specifies the syntax for a full date and time specification. Though folding white space is permitted throughout the date-time specification, it is RECOMMENDED that a single space be used in each place that FWS appears (whether it is required or optional); some older implementations may not interpret other occurrences of folding white space correctly. date-time = [ day-of-week "," ] date FWS time [CFWS] day-of-week = ([FWS] day-name) / obs-day-of-week day-name = "Mon" / "Tue" / "Wed" / "Thu" / "Fri" / "Sat" / "Sun" date = day month year year = 4*DIGIT / obs-year month = (FWS month-name FWS) / obs-month month-name = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" / "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec" day = ([FWS] 1*2DIGIT) / obs-day time = time-of-day FWS zone time-of-day = hour ":" minute [ ":" second ] hour = 2DIGIT / obs-hour minute = 2DIGIT / obs-minute second = 2DIGIT / obs-second zone = (( "+" / "-" ) 4DIGIT) / obs-zone The day is the numeric day of the month. The year is any numeric year 1900 or later. The time-of-day specifies the number of hours, minutes, and optionally seconds since midnight of the date indicated. The date and time-of-day SHOULD express local time. The zone specifies the offset from Coordinated Universal Time (UTC, formerly referred to as "Greenwich Mean Time") that the date and time-of-day represent. The "+" or "-" indicates whether the time-of-day is ahead of (i.e., east of) or behind (i.e., west of) Universal Time. The first two digits indicate the number of hours difference from Universal Time, and the last two digits indicate the number of minutes difference from Universal Time. (Hence, +hhmm means +(hh * 60 + mm) minutes, and -hhmm means -(hh * 60 + mm) minutes). The form "+0000" SHOULD be used to indicate a time zone at Universal Time. Though "-0000" also indicates Universal Time, it is used to indicate that the time was generated on a system that may be in a local time zone other than Universal Time and therefore indicates that the date-time contains no information about the local time zone. A date-time specification MUST be semantically valid. That is, the day-of-the-week (if included) MUST be the day implied by the date, the numeric day-of-month MUST be between 1 and the number of days allowed for the specified month (in the specified year), the time-of-day MUST be in the range 00:00:00 through 23:59:60 (the number of seconds allowing for a leap second; see [STD12]), and the zone MUST be within the range -9959 through +9959.