# Class issues when it comes to Dates Coercion

Here is a function that would let a person create a data frame for trading dates of the year. I am having using the between-function for my end result. Can someone teach me how to deal with this class complexity issue? Please help. This is the function (run the function first to use the later code):

#' Get Trading Dates for one or more years
#'
#' Get a vector of dates of non-holiday weekdays.
#'
#' This uses holiday calendar functions (\code{holidayNYSE} by default)
#' from the \emph{timeDate} package.  If \emph{timeDate} is not loaded, it
#'
#' @param year vector of 4 digit years or something that is coercible to
#'   a vector 4 digit years via \code{as.numeric}
#' @param FUN a function that takes a \code{year} argument and returns a vector
#'   that can be coerced to a \code{Date}.  \code{holidayNYSE} by default. Most
#'   likely, this will be one of:  \sQuote{holidayLONDON}, \sQuote{holidayNERC},
#'   \sQuote{holidayNYSE}, \sQuote{holidayTSX}, \sQuote{holidayZURICH}
#' @return a vector of all dates in \code{years} that are weekdays and not
#'   holidays.
#' @examples
#' \dontrun{
#' }
#' @export
TradingDates <- function(year=format(Sys.Date(), "%Y"), FUN=holidayNYSE) {
# the next few lines should be removed when this code is added to a package
# that Imports timeDate
if (!"package:timeDate" %in% search()) {
suppressPackageStartupMessages({
if (!require(timeDate)) {
stop("timeDate must be installed to use this function.")
}
})
}
## End of code that should be removed when this is added to a package
year <- as.numeric(year)
fun <- match.fun(FUN)
do.call('c', lapply(year, function(y) {
holidays <- as.Date(fun(year=y))
all.days <- seq.Date(as.Date(paste(y, '01-01', sep='-')),
as.Date(paste(y, '12-31', sep='-')), by='days')
nohol <- all.days[!all.days %in% holidays]
nohol[!format(nohol, '%w') %in% c("6", "0")] #neither holiday nor weekend
}))
}

#' Get Date of previous (next) trading day
#'
#' Get the Date of the previous (next) trading day.
#'
#' For \code{PrevTradingDate}, \code{n} is the number of days to go back. So,
#' if \code{n} is 2 and today is a a Monday, it would return the date of the
#' prior Thursday because that would be 2 trading days ago.
#' \code{n} works analogously in \code{NextTradingDate}.
#'
#' The maximum value that \code{n} can be is the total number of days in the
#' year prior to \code{Date} plus the total number of years in the current
#' year of \code{Date}.  So, on the last day of the year, the max value of
#' \code{n} will usually be \code{504} (because most years have 252 trading
#' days).  One the first day of the year, the max value of \code{n} will usually
#' be \code{252}.
#'
#' @param n number of days to go back. 1 is the previous trading day; 2 is the
#'   trading day before that, etc.  \code{n} should be less than 365, but see
#'   details
#' @param Date a \code{Date} or something that can be coerced to a \code{Date}
#' up to, but not including, \code{Date}.  \code{NextTradingDate} returns the
#' date of the next trading day.
#' @author GSee
#' @examples
#' \dontrun{
#' }
#' @export
stopifnot(require(xts)) #remove this line when this is added to a package that Imports xts (needed for first/last)
D <- as.Date(Date)
y <- as.numeric(format(D, "%Y"))
if (length(out) >= n) {
first(last(out, n))
} else {
max.n <- length(out) + length(prev.year.td)
if (n > max.n) stop("'n' is too large. Try something less than 252.")
new.n <- n - length(out) # we need this many trading days from previous year
# if it's the 1st trading day of the year, return the last trading date of
# previous year
}
}

#' @export
stopifnot(require(xts)) #remove this line when this is added to a package that Imports xts (needed for first/last)
D <- as.Date(Date)
y <- as.numeric(format(D, "%Y"))
if (length(out) >= n) {
last(first(out, n))
} else {
max.n <- length(out) + length(next.year.td)
new.n <- n - length(out) # how many trading days we need from next year
if (n > max.n) stop("'n' is too large. Try something less than 252.")
# if it's the last trading day of the year, return the first trading date of
# next year
}
}


Then, to call the function and in an attempt to limit the date range. I wrote the following code:

#listing the dates
StartDate = "2021-01-14"
EndDate = Sys.Date()

filter(between(date, as.Date(StartDate), as.Date(EndDate)))


The error message came back as:

>between() called on numeric vector with S3 class


Can someone explain to me why is this happening and how to fix it! It would be greatly appreciated!

The following code runs for me. You can try

#listing the dates
StartDate = "2021-01-14"
EndDate = Sys.Date()