How to sort files list by date?

Note that you can also sort by accessed time or creation time.
Here's a convenient, parallelized function that can handle whatever you like.

sort_files_by_date <- function(folder_path = '.', search_pattern = NULL, by = 'mtime'){

require(furrr)
require(magrittr)
require(stringr)
require(tidyverse)

  if (!by %>% str_detect('^(m|a|c)time$')) {
    stop('Argument `by` must be one of "mtime", "atime", or "ctime".')
  }

  file_names <-

    # Gets all the file paths for a given path and pattern
    list.files(path = folder_path, pattern = search_pattern, full.names = TRUE) %>%

    # Turns into a one-column tibble (see below)
    tibble(file_names = .)

  files_by_datetime <-

    suppressWarnings(
      future_map_dfr(
        .x = file_names,
        .f = file.info,
        .progress = TRUE,
        extra_cols = FALSE # passed to file.info for performance boost
      )
    ) %>%

    # gets expanded file info, then select the last-modified time and last-accessed time
    select(mtime, atime, ctime) %>%

    # reintroduce our original 'file_names'
    bind_cols(file_names) %>%

    # arrange by descending time (depending on the users choice)
    arrange(
      desc(
        case_when(
          (by == 'mtime') ~ mtime,
          (by == 'atime') ~ atime,
          (by == 'ctime') ~ ctime
        )
      )
    )

  return(files_by_datetime)

}

You can use the file.info function to obtain details on your files. Once you have those details, you can sort the files accordingly. For example,

details = file.info(list.files(pattern="*.csv"))

gives a data frame containing, inter alia, modification and creation times. You can sort that data frame however you want. Here I sort according to modification time, mtime:

details = details[with(details, order(as.POSIXct(mtime))), ]
files = rownames(details)