DateTime: Date-time regexes
In rebus.datetimes: Date and Time Extensions for the 'rebus' Package

OPT_LEADING_0

R Documentation

Date-time regexes

Description

Compound regex constants for matching ISO 8601 dates and times.

Usage

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.

Format

An object of class character of length 1.

An object of class regex (inherits from character) of length 1.

Value

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

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))
)

rebus.datetimes documentation built on Nov. 4, 2022, 1:06 a.m.