Disneyland After Dark is a separate ticketed event that occurs of select nights at Disneyland Park and Disney California Adventure. Each night has a different theme, which coincides with merchandise, food and beverage, ride layovers, entertainment, and more. Each event is four hours long, but you can get into Disneyland three hours before the event starts. Meaning that if it starts at 7:00 pm, you can get in with your ticket at 4:00 pm. These events do tend to sell out, so you're going to want to buy your ticket early. Announced dates and themes include:
Disneyland After Dark: Sweethearts' Nite: February 12 or 13, 2020 at Disneyland Park
Disneyland After Dark: PIXAR Nite: March 5, 2020 at Disney California Adventure Park
Disneyland After Dark: Villains Nite: April 30, 2020 at Disney California Adventure Park
Disneyland After Dark: Star Wars Nite: August 27, 2020 at Disneyland Park