PickyCal

PickyCal lets you add upcoming events to your calendar without importing entire schedules full of things you don't follow. Choose an event source, then filter it to the events you want. Examples include Starship launches, the next James Bond cinema release, and Classic Tetris World Championship finals.

Filters support &, |, !, and parentheses for building filter logic. Subscribe through CalDAV or an ICS link. PickyCal regularly checks for new events and schedule changes, and your calendar picks them up when it syncs.