# Date-time regexes Compound regex constants for matching ISO 8601 dates and times. data ## Format An object of class `character` of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. An object of class `regex` (inherits from `character`) of length 1. ```r OPT_LEADING_0 DTSEP CENTURY CENTURY_IN YEAR YEAR2 YEAR4 MONTH MONTH_IN WEEK_OF_YEAR WEEK_OF_YEAR_IN DAY DAY_IN DAY_SINGLE DAY_OF_YEAR DAY_OF_YEAR_IN WEEKDAY1 WEEKDAY0 HOUR24 HOUR24_SINGLE HOUR24_IN HOUR12 HOUR12_SINGLE HOUR12_IN MINUTE MINUTE_IN SECOND SECOND_IN FRACTIONAL_SECOND FRACTIONAL_SECOND_IN AM_PM TIMEZONE_OFFSET TIMEZONE ISO_DATE ISO_DATE_IN ISO_TIME ISO_TIME_IN ISO_DATETIME ISO_DATETIME_IN YMD YMD_IN YDM YDM_IN MYD MYD_IN MDY MDY_IN DYM DYM_IN DMY DMY_IN HMS HMS_IN HM HM_IN MS MS_IN datetime(x, locale = NULL, io = c("output", "input")) ``` ## Arguments - `x`: A `strptime`-style date-time format string. - `locale`: A string specifying a locale. - `io`: Are you trying to match output or input? The latter is less strict about leading zeroes and spaces. ## Returns A character vector representing part or all of a regular expression. ## Note `"%O[dHImMUVwWy]"`, `"%E[cCyYxX]"`, `"%x"`, `"%X"` and `"%+"` are supposed to be locale-dependent upon output, but implementing this in an OS-portable way seems to be much more effort than it's worth. ## Examples ```r datetime("%m/%d/%Y") # match US style dates twelve_or_twentyfour <- rebus.base::or("%H", "%I%p") datetime(twelve_or_twentyfour) # match hours in 24h or 12h format ## Not run: # week days and months can be matched in any locale if(.Platform$OS.type == "windows") { fr_FR <- "French_France" ar_QA <- "Arabic_Qatar" } else if(Sys.info()["sysname"] != "Darwin") # mac { fr_FR <- "fr_FR" ar_QA <- "ar_QA" } else if(Sys.info()["sysname"] != "Linux") { fr_FR <- "fr_FR.utf8" ar_QA <- "ar_QA.utf8" } datetime("%a %A %b %B", fr_FR) datetime("%a %A %b %B", ar_QA) # All letter tokens. Lots of output. x <- paste0("%", c(letters, LETTERS)) stats::setNames(datetime(x), x) ## End(Not run) # Individual date-time components DTSEP # optional selected punctuation or space CENTURY # exactly two digits YEAR # one to four digits YEAR2 # exactly two digits YEAR4 # exactly four digits MONTH # number from 1 to 12, leading zero WEEK_OF_YEAR # number from 0 to 53, leading zero DAY # number from 1 to 31, leading zero DAY_SINGLE # leading space HOUR24 # 24 hour clock, leading zero HOUR12 # 12 hour clock, leading zero HOUR24_SINGLE # 24 hour clock, leading space HOUR12_SINGLE # 12 hour clock, leading space MINUTE # number from 0 to 59, leading zero SECOND # number from 0 to 61 (leap seconds), leading zero FRACTIONAL_SECOND # a second optional decimal point and up to 6 digits AM_PM # AM or PM, any case TIMEZONE_OFFSET # optional plus or minus, then four digits TIMEZONE # Any value returned by OlsonNames() # ISO 8601 formats ISO_DATE # %Y-%m-%d ISO_TIME # %H:%M:%S ISO_DATETIME # ISO_DATE followed by ISO_TIME, separated by space or "T". # Compound forms, separated by DTSEP YMD YDM MYD MDY DYM DMY HMS HM MS # Some forms have less strict alternatives for input (with an '_IN' suffix). CENTURY_IN MONTH_IN WEEK_OF_YEAR_IN DAY_IN HOUR24_IN HOUR12_IN MINUTE_IN SECOND_IN FRACTIONAL_SECOND_IN ISO_DATE_IN ISO_TIME_IN ISO_DATETIME_IN YMD_IN YDM_IN MYD_IN MDY_IN DYM_IN DMY_IN HMS_IN HM_IN MS_IN dates <- seq(as.Date("2000-01-01"), as.Date("2001-01-01"), "1 day") datetimes <- seq(as.POSIXct(Sys.Date()), as.POSIXct(Sys.Date() + 1), "1 sec") times <- substring(format(datetimes), 12, 19) stopifnot( all(grepl(ISO_DATE, dates)), all(grepl(ISO_TIME, times)), all(grepl(ISO_DATETIME, datetimes)) ) non_dates <- c( "2000-13-01", "2000-01-32", "2000-00-01", "2000-01-00" ) non_times <- c( "24:00:00", "23:60:59", "23:59:62", "23 59 59" ) stopifnot( all(!grepl(ISO_DATE, non_dates)), all(!grepl(ISO_TIME, non_times)) ) ``` ## See Also `strptime` that describes formatting codes, `ClassGroups`, `Sys.setlocale`

DateTime function