5. 日期和时间的规范
5.1. 语法
date-time = [ day "," ] date time ; dd mm yy
; hh:mm:ss zzz
day = "Mon" / "Tue" / "Wed" / "Thu"
/ "Fri" / "Sat" / "Sun"
date = 1*2DIGIT month 2DIGIT ; day month year
; e.g. 20 Jun 82
month = "Jan" / "Feb" / "Mar" / "Apr"
/ "May" / "Jun" / "Jul" / "Aug"
/ "Sep" / "Oct" / "Nov" / "Dec"
time = hour zone ; ANSI and Military
hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
; 00:00:00 - 23:59:59
zone = "UT" / "GMT" ; Universal Time
; North American : UT
/ "EST" / "EDT" ; Eastern: - 5/ - 4
/ "CST" / "CDT" ; Central: - 6/ - 5
/ "MST" / "MDT" ; Mountain: - 7/ - 6
/ "PST" / "PDT" ; Pacific: - 8/ - 7
/ 1ALPHA ; Military: Z = UT;
; A:-1; (J not used)
; M:-12; N:+1; Y:+12
/ ( ("+" / "-") 4DIGIT ) ; Local differential
; hours+min. (HHMM)
5.2. 语义
原文：
If included, day-of-week must be the day implied by the date
specification.
Time zone may be indicated in several ways. "UT" is Univer-
sal Time (formerly called "Greenwich Mean Time"); "GMT" is per-
mitted as a reference to Universal Time. The military standard
uses a single character for each zone. "Z" is Universal Time.
"A" indicates one hour earlier, and "M" indicates 12 hours ear-
lier; "N" is one hour later, and "Y" is 12 hours later. The
letter "J" is not used. The other remaining two forms are taken
from ANSI standard X3.51-1975. One allows explicit indication of
the amount of offset from UT; the other uses common 3-character
strings for indicating time zones in North America.
翻译：
