r - how to convert date and time from character to datetime type

Question

hi how shall i convert this to a datetime type object which preserves both the date and the time?

DateTime="2007-02-01 00:00:00"

Tried

as.Date(DateTime,'%Y-%m-%d %H:%M:%S') 

but doesn't returns the time part. couldn't figure out how after trying strptime and lubridate. thanks.

Answer 1

As @Richard Scriven pointed out, you shouldn't be using as.Date because it's not a datetime class. Here are a few different ways:

DateTime <- "2007-02-01 00:00:00"
DateTime2 <- "02/01/2007 00:06:10"
## default format Y-m-d H:M:S
> as.POSIXct(DateTime,tz=Sys.timezone())
[1] "2007-02-01 EST"
> as.POSIXlt(DateTime,tz=Sys.timezone())
[1] "2007-02-01 EST"
##
## specify format m/d/Y H:M:S
> as.POSIXct(DateTime2,format="%m/%d/%Y %H:%M:%S",tz=Sys.timezone())
[1] "2007-02-01 00:06:10 EST"
> as.POSIXlt(DateTime2,format="%m/%d/%Y %H:%M:%S",tz=Sys.timezone())
[1] "2007-02-01 00:06:10 EST"
##
## using lubridate
library(lubridate)
> ymd_hms(DateTime,tz=Sys.timezone())
[1] "2007-02-01 EST"
> mdy_hms(DateTime2,tz=Sys.timezone())
[1] "2007-02-01 00:06:10 EST"

You don't have to specify format= for as.POSIXct and as.POSIXlt when you have the %Y-%m-%d %H:%M:%S format. In other cases, like %m/%d/%Y %H:%M:%S, you usually have to specify the format explicitly.