Quickly convert local timestamps to a POSIXct vector

fast_POSIXct.r

#' fast_POSIXct
#'
#' Quickly convert local timestamps to a POSIXct vector
#'
#' @param   x   timestamps (YYYY-mm-dd HH:MM:SS)
#' @param   tz  local timezone
#' @return      POSIXct vector
#' @export
fast_POSIXct <- function(x, tz) {
    stopifnot(is.character(x))
    require(fasttime)
    GMT <- fasttime::fastPOSIXct(x, tz='GMT')
    epoch <- as.numeric(GMT)
    z <- as.POSIXct(epoch, tz=tz, origin='1970-01-01')
    adjusted <- z - as.POSIXlt(z)$isdst * 3600
    return(adjusted)
}