The names_months() function produces a vector of all short month names
used by the bigD package.
names_months()A character vector of short month names.
# Let's get all the short month names with
# the `names_months()` function
names_months()
#> [1] "jan" "feb" "mar" "apr" "may" "jun" "jul" "aug" "sep" "oct" "nov" "dec"