Switch timevis labels to portuguese in R

Question

I was trying the timevis package in R Markdown, but was not able to change the labels to portuguese, despite theoretically having a visjs support for it.

A reproducible example would be:

library(timevis)

data <- data.frame(
    id      = 1:4,
  content = c("Item one"  , "Item two"  ,"Ranged item", "Item four"),
  start   = c("2016-01-10", "2016-01-11", "2016-01-20", "2016-02-14 15:00:00"),
  end     = c(NA          ,           NA, "2016-02-04", NA)
)

timevis(data,options = list(locale = "fr")) #change to french, works

timevis(data,options = list(locale = "pt")) #change to portuguese, does not work

And I tried several options, like "pt-BR", "pt-PT","PT".

Anyone would be able to help?