California QSO Party
The California QSO Party (CQP) is held every year on the first weekend of October. The first CQP took place in 1966. Since 1974, the Northern California Contest Club (NCCC) has sponsored CQP. CQP has traditionally opened the annual contest season by providing an opportunity for contesters to prepare for the ARRL November Sweepstakes since the format is similar. Stations outside of California, worldwide, work stations in California only. The 58 counties of CA are the multipliers. California stations work all stations in or out of CA. The 50 US states and 13 Canadian provinces/territories are the multipliers. Stations outside of Canada and the US add to one's QSO total but do not count as multipliers. See the full set of CQP Rules for more details.
Link to California QSO Party webpages
First weekend in October; 1600z Saturday to 2200z Sunday