Which time zone mod best defeats spammers?
 

I was very spam free until 2 weeks ago. I use a human verification question. Recently I started getting spammer registrants so I added back "email validation" after having dropped it a while ago...since some legitimate registrants are blocked that way.

So the new spammers are all from the China time zone and so far they haven't been getting past the "email validation" that I added a few days ago. Until today...when the first successful spammer got past this. But they all come up with China time zones so I would like to add a mod to take care of this.

Are there more than one to choose from and if so which is best?

Very interessting.
Never looked at this by spammers, i think that would be a good way for spammeranalyse.

(i'm looking for ways against spammers to build in my modification)