converting datetime string to POSIXct date/time format in R

string r datetime posixct
CFrench picture CFrench · Feb 10, 2014 · Viewed 41k times · Source

Consider a string in the format 

test <- "YYYY-MM-DDT00:00:00.000-08:00"

My goal is to convert those strings to POSIXct format so that I can plot the data. my initial thought was to use

as.POSIXct(test)

...but that seems to truncate the datetime to just date. Any thoughts? The help info for as.POSIXct seems to imply that the input should be date and time separated by a space, not by a "T". Is this my issue?

Answer

thelatemail picture thelatemail · Feb 10, 2014

You need to specify a format for your conversion. Take a read of ?strptime to see all of the options for date formats.

#YYYY-MM-DDT00:00:00.000-08:00
test <- "2013-12-25T04:32:16.500-08:00"
z <- as.POSIXct(test,format="%Y-%m-%dT%H:%M:%OS")
op <- options(digits.secs = 3)
z
#[1] "2013-12-25 04:32:16.5 EST"

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