Rated 5 out of 5 stars

Got a warning when logging onto the php|architect website. See http://i49.tinypic.com/11kfrmb.jpg for screenshot - note that it gves a certificate issued on April 17, 2009 as being from *28 days ago* and thus not due yet. Version is 1.2.6 on FF 3.6.3, WinXP Pro SP3, current date (July 1st, 2010) is correct both on my PC and in the response HTTP header from phparch.com.
I have no idea where is the addon getting a wrong date from.
Very good tool otherwise - I do reccomend this to everybody.

This review is for a previous version of the add-on (1.2.6). 

Just ignore it

This is due to the date parsing bug in older versions of CP. Since you have been using CP so long, some of the certificates in your database have messed up date (2009-17-04 would be the 17th month of 2009, that's why it computed as last month for you). Just replace those buggy entries in your database with the new certificates and this will no longer occur. Sorry for taking a while to understand what's happening here and getting back to you.