Andre and me learned yesterday from Sumana that bug days were held previously on a weekly basis. This might complicate things, although maybe actually not. A possibility:
1. Pick a day e.g. "Thursday is Bug Day!"
2. Find a small task / area in Bugzilla e.g. "Let's clean MediaWiki Extensions >> Drafts" https://bugzilla.wikimedia.org/buglist.cgi?list_id=172051&resolution=---...
3. Take a chat room less noisy than #mediawiki, or create one just for the occasion.
4. Define a list of nicknames you, Andre, etc (and their availability that day. Define also 4 hours of higher intensity where all of you will be there and focusing on the Bug Day activity.
5. Announce the day before to wikitech-l, mediawiki-l and optionally to any other relevant list.
6. Keep all this up to date at https://www.mediawiki.org/wiki/Bug_management/Meeting_preparations or the alternative page of your choice.
It feels like more work, but then again choosing smaller topics is easier and if a week goes meh then it's not a big deal.