Virus Definition Updates

I haven’t been paying much attention and I’m curious about something. How often do the Avast AV definitions get updated? Is it daily, every few days, or as needed?

Funny question as I guess you use avast! for a longer period.
Between several times a day or as needed AND that even on sun- and holidays
Usually you get a little blue pop up window in the lower right corner AND also a spoken text “virus database has been updated” after the VPS has been updated…

This page will give you an overview of how often it is updated: http://www.avast.com/eng/vps_history.html