DR HHH's window period claim for hiv testing

there is quite a bit of certainty on the certainty of window period being 6-8 weeks instead of the official suggested 3 month by CDC for current HIV antibody testing. I'm questioning whether this is based on evidence based literature or expert experience and opinion. And whether rapid testing warrants the same window period

[Teak]

The guidelines from the manufacture of the tests is 3 months.

[worriedwell29]

The doctors forum has a recent blog on this issue.

http://www.medhelp.org/posts/HIV-Prevention/what-is-the-window-period-for-hiv/show/1704700