- From: Julian Reschke <julian.reschke@greenbytes.de>
- Date: Thu, 2 Aug 2018 16:01:48 +0200
- To: RFC Errata System <rfc-editor@rfc-editor.org>, fielding@gbiv.com, ben@nostrum.com, aamelnikov@fastmail.fm, adam@nostrum.com, mnot@mnot.net, pmcmanus@mozilla.com
- Cc: magnar@myrtveit.com, ietf-http-wg@w3.org
On 2018-08-02 15:31, RFC Errata System wrote: > The following errata report has been submitted for RFC7231, > "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content". > > -------------------------------------- > You may review the report below and at: > http://www.rfc-editor.org/errata/eid5448 > > -------------------------------------- > Type: Technical > Reported by: Magnar Ovedal Myrtveit <magnar@myrtveit.com> > > Section: 7.1.1.1 > > Original Text > ------------- > Recipients of a timestamp value in rfc850-date format, which uses a > two-digit year, MUST interpret a timestamp that appears to be more > than 50 years in the future as representing the most recent year in > the past that had the same last two digits. > > Corrected Text > -------------- > Recipients of a timestamp value in rfc850-date format, which uses a > two-digit year, MUST interpret a timestamp that appears to be more > than 200 years in the future as representing the most recent date in > the past that also matches the timestamp. > > Notes > ----- > The combination of day-of-the-week, day-of-the-month, month, and the two last digits of the year repeats every 400 years. For example, "Friday, 01-Jan-00 00:00:00 GMT" (as formatted by rfc850) happens in the years ...1300, 1700, 2100, 2500, 2900... > > With the original text, "Friday, 01-Jan-00 00:00:00 GMT" is interpreted as year 2000, since year 2100 is more than 50 years in the future, and year 2000 is the most recent year in the past with the same last two digits as 2100. However, if it really was year 2000, it should have said "Saturday, 01-Jan-00 00:00:00 GMT". So it would make more sense to interpret it as either year 1700 or year 2100. The corrected text interprets it as year 2100. > > "Monday, 01-Jan-00 00:00:00 GMT" happens in years ...1100, 1500, 1900, 2300, 2700..., and is interpreted as year 1900, since 2300 is more than 200 years in the future. > ... The text in RFC7231 is not incorrect, it's just not optimal. It's debatable whether a more complex rule for handling two-digit years really is an improvement, given the fact that the use of that date format is discouraged already. Best regards, Julian
Received on Thursday, 2 August 2018 14:04:56 UTC