Depends what you're waiting for. Personally I'd say about 15-20 minutes is the max for something you can easily get elswhere (like food or many consumer items),

Depends what you're waiting for. Personally I'd say about 15-20 minutes is the max for something you can easily get elswhere (like food or many consumer items), 30-40 minutes would be a good maximum for methods of transport wherever there are alternative routes available, and you should only wait indefinitely if you're 100% certain whatever you're waiting for is only available at that location on that day/at that time.