[R] Dates in read.spss

[Thomas Lumley]

On Mon, 21 Apr 2003, Frank E Harrell Jr wrote:

> I am using read.spss in the foreign package to read an SPSS save file.
> For date variables I get huge values such as 11489990400.  Does anyone
> know how to convert these values to R POSIXct date objects?  Thanks in
> advance -Frank
>

I believe it is

ISOdate(1584,10,14)+11489990400

that is, the dates are seconds since 14 October 1584

I don't know if R and SPSS necessarily agree on how long ago that was on
all machines, though.

	-thomas