Social task - Watch a movie at a neighbor's house between 6 PM and 11 PM
A time sensitive task. This will only clear if you do it within a specific time slot, in this case between 6PM (18:00 for us Europeans) and 11PM (23:00).
Click on the globe or the party boat to visit your neighbor. Click on a house that has a TV to take your sim to this house.
When the time is right simply click on the TV and select option Watch a movie. The task should clear instantly if you do it right.