The Responsa Project makes updates once a year between Passover and after Chanukah depending on how much is completed.
In recent years (at least since version 10 in 2002), the Responsa Project has made updates available once a year, usually between the Passover and Shavuot holidays, although this varies considerably. Sometimes they release an update after the holiday of Chanukah or after the holiday of Purim. It depends on how much they have completed. 
