[R] Convert ordinary dates into POSIX

[Gabor Grothendieck]

There is a discussion and code in the R News 4/1 help desk article.

On 11/8/06, Ivan Kalafatic <ivan.kalafatic at gmail.com> wrote:
> Does anyone know where I can find any tool for Windows that converts
> dates from ordinary formats into POSIX?
> I need it to import sime time series from Excel into R and use them
> with its package.
>
> Thanks!