ISOweek (version 0.6-2)

date2ISOweek: Converts date from standard notation to week notation according to ISO 8601

Description

This function returns the year, the week of the year, and the day of week of a given date according to ISO 8601. It is an substitute for the %Y-W%V-%u format which is not implemented on Windows.

Usage

date2ISOweek(date)

Arguments

date

Vector which can be coerced to class Date

Value

A character vector of year, week, and weekday in format "%Y-W%V-%u"

Details

According to ISO 8601, the year of the week can differ from the calendar year (see the examples).

See Also

strptime for a description of the date formats and references on ISO 8601.

Examples

x <- paste(1999:2011, "-12-31", sep = "")
y <- as.Date(x)
data.frame(date = format(y), weekdate = date2ISOweek(y))
data.frame(date = x, weekdate = date2ISOweek(x))