Here is a summary of the events that have taken place in WhuddleWorld.
Those events are over now, to learn about the next event you can check WW's front page and the BBB Board, which usually warns users of events in advance.

2005
Halloween
Thanksgiving
Christmas

2006
Snowball Fight
Valentine's Day
WW's Landslide
1st Anniversary
Beta Testing
"Where oh where are shops" Quest
Bazaar Opening
"Nature's Architect" Contest
"Back To School" Scavenger Hunt
Sponsor Shop
Boo!dle Day
Charlie and Chelsea's Registration Rally
Gathering Day
Winter Festival

2007
50,000 Citizens Celebration
Frifuzzle Day
2nd Anniversary
April Fool's Day
Bofa Day