This FAQ discusses the basic ways of setting up scenarios.
(March 2018: All of the following applies only to the SmartThings Classic app. If you purchased your hub after March 1, 2018 and are using the new “SmartThings (Samsung Connect)” app, creating rules works differently.)
You’ve got your hub. You’ve got some devices. Now how do you schedule what happens when?
SmartThings doesn’t have a rules engine/scheduler, so there’s no one tutorial for how to do this. But it’s an open platform, and there are about 12 different ways to set up various kinds of schedules. Some require custom code, some don’t.
A “scheduler” in this context is anything that causes a networked device to perform an action, even if it’s just to toggle on or off immediately. (Network engineering definition, forgive me.
For specifics, there’s no question that core is currently the most powerful method:
CoRE (now WebCore) is a very powerful community – created rules engine for SmartThings. It allows you to set up stacked conditionals like “If A then B but only while C and not if D.”
Setting it up can be quite complex, but there are many community members who will be glad to help you.
For example, here is a piston that one member created to notify him if the dog had already been fed twice that day and he picked up the dog bowl for a third time. He needed this because he has a large family and people didn’t always remember whose turn it was to feed the dog.
If you have an android phone, the third-party app, sharp tools, allows you to create an integration between smart things and Tasker which then enables many third-party integrations.
Or, as others have mentioned, smartthings does have an IFTTT channel. And it allows you to create virtual switches. So once you combine those, you have a very powerful IFTTT function.