Tue. 23rd August, 2011
You may fix bugs at any time, but joining in a Bug Day makes it funnier, exchanging ideas and review requests via IRC (irc://irc.freenode.net/#typo3-bugday). The atmosphere is generally quite stimulating.
This is a companion discussion topic for the original entry at https://typo3.org/article/next-bug-day-august-26/