Usually 2 weeks when it's obvious they are not playing. Sometimes real life gets in the way, especially on long events when people may be on holiday with no access to wifi etc. This event I've been a little ruthless, I've done my best to visit all my neighbours daily, and noticed a few that were playing (plenty of monorail track in their towns) but continually not returning a visit to my town. Bye Bye, why bother having a neighbour if they are never going to reciprocate and help you. That's the inherent problem with neighbour visits that this event has, the blue print cap means that some neighbours don't visit you if you are further down the alphabetical list once they've reached their maximum available from visits per day.
