Obtaining dates using other dates (or month or year) as reference

Source: R/getdate.R

Imagine you have one date and want the first or last day of this date's month. For example, you have the date 2018-02-01 and want the last day of its month. You have to check whether or not its year is a leap year, and this sounds a tough task. getdate helps with returning specific dates according to a reference than can be another date, a month or an year.

getdate(expr, ref, cal = bizdays.options$get("default.calendar"))

Arguments

expr

a character string specifying the date to be returned (see Details)

ref

a reference which represents a month or year, where the date has to be found.

cal

the calendar's name

Value

a vector of dates according to a reference (month or year)

Details

expr represents the day has to be returned, here it follows a few examples:

  • "second day"

  • "10th bizday"

  • "3rd wed"

  • "last bizday"

  • "first fri"

expr is a character string with two terms: "<position> <day>"

  • positions: first or 1st, second or 2nd, third or 3rd, last and XXth (examples 6th or 11th)

  • days: day, bizday, or weekdays (sun, mon, tue, wed, thu, fri, sat)

getdate returns dates according to a reference that can be a month or an year. This reference can be passed as a character vector representing months or years, or as a numeric vector representing years. The ISO format must be used to represent years or months with character vectors.

Examples

getdate("10th wed", 2018, "Brazil/ANBIMA")
#> [1] "2018-03-07"
getdate("last bizday", 2010:2018, "Brazil/ANBIMA")
#> [1] "2010-12-31" "2011-12-30" "2012-12-31" "2013-12-31" "2014-12-31"
#> [6] "2015-12-31" "2016-12-30" "2017-12-29" "2018-12-31"
dts <- seq(as.Date("2018-01-01"), as.Date("2018-12-01"), "month")
getdate("first bizday", format(dts, "%Y-%m"), "Brazil/ANBIMA")
#>  [1] "2018-01-02" "2018-02-01" "2018-03-01" "2018-04-02" "2018-05-02"
#>  [6] "2018-06-01" "2018-07-02" "2018-08-01" "2018-09-03" "2018-10-01"
#> [11] "2018-11-01" "2018-12-03"
getdate("last bizday", Sys.Date(), "Brazil/ANBIMA")
#> [1] "2025-01-07"
getdate("next bizday", Sys.Date(), "Brazil/ANBIMA")
#> [1] "2025-01-09"
getdate("2nd wed", Sys.Date())
#> [1] "2025-01-15"
getdate("next wed", Sys.Date())
#> [1] "2025-01-15"
getdate("last wed", Sys.Date())
#> [1] "2025-01-01"
getdate("next mon", Sys.Date())
#> [1] "2025-01-10"
getdate("last mon", Sys.Date())
#> [1] "2025-01-03"