Convert UNIX epoch to Date object
I'm plotting and performing calculations on uniformly distributed time series. The timestamps are currently stored as integers representing the number of seconds since the UNIX epoch (e.g. 1352068320
), but Date
objects seem more appropriate for plotting. How can I do the conversion?
I've read ?Date
, ?as.Date
and ??epoch
, but seem to have missed that information.
Solution 1:
Go via POSIXct
and you want to set a TZ
there -- here you see my (Chicago) default:
R> val <- 1352068320
R> as.POSIXct(val, origin="1970-01-01")
[1] "2012-11-04 22:32:00 CST"
R> as.Date(as.POSIXct(val, origin="1970-01-01"))
[1] "2012-11-05"
R>
Edit: A few years later, we can now use the anytime package:
R> library(anytime)
R> anytime(1352068320)
[1] "2012-11-04 16:32:00 CST"
R> anydate(1352068320)
[1] "2012-11-04"
R>
Note how all this works without any format or origin arguments.
Solution 2:
With library(lubridate)
, numeric representations of date and time saved as the number of seconds since
1970-01-01 00:00:00 UTC, can be coerced into dates with as_datetime()
:
lubridate::as_datetime(1352068320)
[1] "2012-11-04 22:32:00 UTC"