How to convert unix timestamp (milliseconds) and timezone in R?

Question

I have data which has two columns time and timezone that have the timestamp of events. Examples are:

time               timezone
14         


        

Answer 1

It looks like the timezone column is the timezone offset, in milliseconds. I assume that means the timezone column will adjust for daylight saving time manually

So you should add the time and timezone columns before converting to POSIXct. You should also set the tz to "UTC" so no DST adjustments will be made to your POSIXct object.

R> time <- 1433848856453
R> timezone <- 10800000
R> options(digits.secs=3)
R> .POSIXct((time+timezone)/1000, tz="UTC")
[1] "2015-06-09 14:20:56.453 UTC"

Answer 2

I think this can be right for you.

aa <- 1433848856453
as.POSIXct(aa/1000, origin="1970-01-01")
[1] "2015-06-09 13:20:56.453 CEST"

Edit

Now I've realized that my code is not reproducible, because of my personal settings, but this can fix it and let you achieve the goal.

options(digits.secs=6)