While I like and use dplyr time to time, I wish it could handle POSIXlt datetime. Also, it seems to barf on some dataframes just because the df contained a column format, dplyr doesn't support even if it is not being used in processing.
just use lubridate, it has a lot less headache to it.
my beef is with the new tibble-ish format of dplyr. the format doesn't support lists as cells, unlike data frames. right now, `tbl_df` is a good in-between, but since dplyr is converging to the tibble/feather format, it's gonna be rough
