ISO year to last date (Sunday)

Returns the date of the Sunday that ends the last ISO week of a given ISO year.

Usage

isoyear_to_last_date(x)

# Default S3 method
isoyear_to_last_date(x)

# S3 method for class 'character'
isoyear_to_last_date(x)

# S3 method for class 'numeric'
isoyear_to_last_date(x)

Arguments

x

ISO year as a number or character string, e.g. 2020 or "2020".

Value

A base::Date vector giving the last Sunday of each ISO year.

Details

ISO weeks end on Sunday, so the returned date is the Sunday of the final ISO week. ISO years and calendar years are not aligned. The returned date can therefore fall in early January of the following calendar year. For example, the last date of ISO year 2020 is 2021-01-03. The function accepts the year as either a number or a character string.

See also

isoyear_to_last_isoweek_n() and isoyear_to_last_isoyearweek_c() answer the same question as a week number and as a yearweek string. isoyearweek_to_last_date() and season_to_last_date() do the same for an ISO yearweek and for a season. vignette("date_conversion", package = "cstime") for worked date, ISO year and ISO week conversions. No vignette runs this function.

Examples

isoyear_to_last_date(c(2019, 2020, 2021))
#> [1] "2019-12-29" "2021-01-03" "2022-01-02"
isoyear_to_last_date("2020")
#> [1] "2021-01-03"