r - character string is not in a standard unambiguous format

Question

I have a dataframe (df3) with with some values.

One of these values is the daedlines.

The data of this value is something like the following:

deadline
1419397140
1418994978
1419984000
1418702400

They are days and I want to convert the to using this:

df3$deadline <- as.POSIXct(df3$deadline, origin="1970-01-01")

Generally it was worked for me with other dataframes from other files.

However with this it gives me back this error:

Error in as.POSIXlt.character(as.character(x), ...) : 
  character string is not in a standard unambiguous format

How can I fix it?

Answer 1

It might be that you have a character or factor, and it's expecting a numeric vector for conversion from unix time :

as.POSIXct(as.numeric(as.character(df3$deadline)),origin="1970-01-01")