Game A Week
This one is informal, and doesn't have a strong community yet, but it is growing. It is promoted by Adrieal Wallick, here's her GDC talk http://www.gamasutra.com/view/ne...
0h Game Jam
During DST hour shift, we shift clocks backwards, so there's actually 1 hour between 2:00 am and 2:00 am. This is the best time in the year to make a game! Make a game in zero