How to convert a date from a character string?

Question

I have searched but I could not find out how to convert a date from a character string formatted as follows:

date <- "07-21-2015-09:30AM"

I wanted to use as.Date, but I have not manage to. All I get is the following:

as.Date(date, format="%m-%d-%y-%hAM")
NA

as.Date(dates, format="%m-%d-%y-%h")
NA

Answer 1

I like strptime for this:

strptime(date, format="%m-%d-%Y-%R%p")
#[1] "2015-07-21 09:30:00 EDT"

And in the case that you needed to see the date in the same format as entered, you can call the related strftime. It doesn't change the internal storage of the variable, rather it changes the format only.

strftime(xx, format="%m-%d-%Y-%R%p")
#[1] "07-21-2015-09:30AM"

Answer 2

If we need the 'date' and 'time', one option is as.POSIXct

 as.POSIXct(date, format='%m-%d-%Y-%I:%M%p')
 #[1] "2015-07-21 09:30:00 EDT"

Answer 3

You can also use the lubridate package like this:

library('lubridate')
date <- "07-21-2015-09:30AM"
mdy_hm(date)
# "2015-07-21 09:30:00 UTC"