R/dttm_diff.r

In vbfelix/relper: Miscellaneous Functions for Data Preparation, Cleaning, and Visualization

#' Difference between two dates
#'
#' @description Computation of the difference between two dates (date2 - date1 + add).
#'
#' @eval arg_value("date1","date")
#' @eval arg_value("date2","date")
#' @eval arg_value("add","numeric",default = "0")
#' @eval arg_date_unit("unit")
#'
#' @return A numeric single value with the computed difference between the two dates.
#'
#' @export
#'
#' @examples
#'
#' date1 <- lubridate::dmy("01/05/1998")
#'
#' date2 <- lubridate::dmy("21/11/2018")
#'
#' dttm_diff(date1 = date1,date2 = date2,unit = "days")

dttm_diff <-
  function(
    date1,
    date2,
    add = 0,
    unit = c("days","secs", "mins", "hours","weeks")
  ){

    stopifnot(relper::is_date(date1) | relper::is_datetime(date1))

    stopifnot(relper::is_date(date2) | relper::is_datetime(date2))

    stopifnot(length(date1) == length(date2))

    stopifnot(is.numeric(add),length(add) == 1)

    stopifnot(is.character(unit))

    unit <- match.arg(unit)

    output <- as.numeric(difftime(date2,date1,units = unit)) + add

    return(output)

  }