You can do something like this
library(dplyr)
sample_df <- data.frame(
time_stamp = c("4/12/2016 7:21:00 AM")
)
sample_df %>%
mutate(time_stamp = mdy_hms(time_stamp),
date = as.Date(time_stamp),
time = strftime(time_stamp, format="%H:%M:%S", tz = "UTC"))
#> time_stamp date time
#> 1 2016-04-12 07:21:00 2016-04-12 07:21:00
Created on 2022-11-11 with reprex v2.0.2
Note: Next time please provide a proper REPRoducible EXample (reprex) illustrating your issue.