By mid-afternoon on Saturday, Disneyland Park stopped admitting new guests and suggested that they visit Disney California Adventure instead. The restriction was in place over 5 hours.
Saturday was one of many Grad Nites that are held for high school seniors from around the southwest. What was once an after-hours party at Disneyland Park changed a few years ago. Students now receive a Park Hopper ticket good for both parks that they can use during the day, then after California Adventure closes, they head there for their exclusive party.
This weekend was also one of the final chances for Southern California residents to purchase and use a special ticket offer that brought the cost of a day in the park under $50. Southern California residents were allowed to purchase a 3-day 1-park ticket at only $149, which is significantly less than the $270 regular price for the same ticket. They were also allowed to use their 3-days anytime during the offer period, instead of the ticket expiring after 13 days like regular tickets do.
At 8:45pm, admittance restrictions to Disneyland Park were finally lifted.
Source: Disneyland/@Disneyland Today