Social task - Play sim city on a neighbor's computer between 8pm and 8 am.
A time sensitive task. This will only clear if you do it within a specific time slot, in this case between 8PM (20:00 for us Europeans) and 8AM (08:00).
Click on the globe or the party boat to visit your neighbor, select an adult sim for this task.
Click on the house that contains a computer to take your sim to this house. Click on the computer and select option Play Sim City. If you do it in the specified time interval the task will clear instantly.