Here's the current from Bart's web page on parking:
"***All stations offer Extended Weekend parking which allows BART riders to park their vehicle from the start of train service on Friday to 2:00 am Monday. BART riders at stations where there is a daily fee requirement (currently Daly City and Colma Stations) must pay the daily fee for Friday. Should a designated holiday (see below) fall on a Friday patrons are allowed to park from the start of train service on Thursday until 2:00 am Monday. Should one of the designated holidays fall on a Monday patrons are allowed to park from the start of train service on Friday until 2:00 am Tuesday."
I've found the Millbrae and Colma stations safe but would have some qualms about Daly City.