is there a way to modify the date when signing?

[Anonymous]

On Wed, 22 May 2013 11:59:37 +0200
Werner Koch <wk at gnupg.org> wrote:

> On Tue, 21 May 2013 23:55, mixmaster at remailer.privacy.at said:
>   
> > I would like to sign all my messages and have it appear to be
> > signed on the Epoch date 1970...unless there is some other default
> > way gnupg   
> 
> Don't do that; there was no OpenPGP in 1970 and on some systems you
> may run into problems.  If you want to use a faked date, better use
> 2001-01-01 or so.
> 
> With newer versions of GnuPG-2 you may use
> 
>   --faked-system-time 20010101T000000
> 
> alternative use seconds since Epoch.
>   

This is not working on my gnupg 2.0.20 or 2.0.19.  invalid option error.
I don't know what version I should be using, because the man page
option --try-secret-key also gives an error.  It does show the option
in my man page.