Re: ISO 8601 ABNF grammar

[Tim Howes <howes@xxxxxxxxxxxx>]

Chris, this is great. We need this in the MIME-DIR document
as well. Any chance of you putting this into an Internet
Draft, that could be progressed along with the documents
that need it? This seems more sensible than including the
BNF in multiple documents.                     -- Tim

Chris Newman wrote:
> 
> I did my best attempt to write a complete ABNF grammar for ISO 8601.
> Incidentally, I suggest we don't use the complete grammar in the
> calendaring specification, as I think it's far too complex.
> 
> I'll also note that if the "T" is omitted from date-time, as 8601 permits,
> then the grammar is ambiguous.
> 
> I do not have access to the 1991 Corregendum at present.
> 
> ------
> ISO 8601:1988 ABNF
> 
> Dates:
> 
> date-century      = 2DIGIT  ; 00-99
> date-decade       =  DIGIT  ; 0-9
> date-subdecade    =  DIGIT  ; 0-9
> date-year         = date-decade date-subdecade
> date-fullyear     = date-century date-year
> date-month        = 2DIGIT  ; 01-12
> date-wday         =  DIGIT  ; 1-7
> date-mday         = 2DIGIT  ; 01-28, 01-29, 01-30, 01-31 based on month/year
> date-yday         = 3DIGIT  ; 001-365, 001-366 based on year
> date-week         = 2DIGIT  ; 01-52
> 
> datepart-fullyear = [date-century] date-year ["-"]
> datepart-ptyear   = "-" [date-subdecade ["-"]]
> datepart-wkyear   = datepart-ptyear / datepart-fullyear
> 
> dateopt-century   = "-" / date-century
> dateopt-fullyear  = "-" / datepart-fullyear
> dateopt-year      = "-" / (date-year ["-"])
> dateopt-month     = "-" / (date-month ["-"])
> dateopt-week      = "-" / (date-week ["-"])
> 
> datespec-full     = datepart-fullyear date-month ["-"] date-mday
> datespec-year     = date-century / dateopt-century date-year
> datespec-month    = "-" dateopt-year date-month [["-"] date-mday]
> datespec-mday     = "--" dateopt-month date-mday
> datespec-week     = datepart-wkyear "W" (date-week / dateopt-week date-wday)
> datespec-wday     = "---" date-wday
> datespec-yday     = dateopt-fullyear date-yday
> 
> date              = datespec-full / datespec-year / datespec-month /
>                 datespec-mday / datespec-week / datespec-wday / datespec-yday
> 
> Times:
> 
> time-hour         = 2DIGIT ; 00-24
> time-minute       = 2DIGIT ; 00-59
> time-second       = 2DIGIT ; 00-60
> time-fraction     = ("," / ".") 1*DIGIT
> time-numzone      = ("+" / "-") time-hour [[":"] time-minute]
> time-zone         = "Z" / time-numzone
> 
> timeopt-hour      = "-" / (time-hour [":"])
> timeopt-minute    = "-" / (time-minute [":"])
> 
> timespec-hour     = time-hour [[":"] time-minute [[":"] time-second]]
> timespec-minute   = timeopt-hour time-minute [[":"] time-second]
> timespec-second   = "-" timeopt-minute time-second
> timespec-base     = timespec-hour / timespec-minute / timespec-second
> 
> time              = timespec-base [time-fraction] [time-zone]
> 
> date-time         = date ["T"] time
> 
> Durations (periods):
> 
> dur-second        = 1*DIGIT "S"
> dur-minute        = 1*DIGIT "M" [dur-second]
> dur-hour          = 1*DIGIT "H" [dur-minute]
> dur-time          = "T" (dur-hour / dur-minute / dur-second)
> dur-day           = 1*DIGIT "D"
> dur-week          = 1*DIGIT "W"
> dur-month         = 1*DIGIT "M" [dur-day]
> dur-year          = 1*DIGIT "Y" [dur-month]
> dur-date          = (dur-day / dur-month / dur-year) [dur-time]
> 
> duration          = "P" (dur-date / dur-time / dur-week)
> 
> Periods:
> 
> period-explicit   = date-time "/" date-time
> period-start      = date-time "/" duration
> period-end        = duration "/" date-time
> 
> period            = period-explicit / period-start / period-end