Smart home assistants need smarter timers. Today, you can use Alexa, Google Assistant or Siri to set timers. You can use all three smart assistants to control your smart interfaces. But frustratingly, you can't use the two features together: putting your lights on good will for 30 minutes is impossible with today's most sophisticated, cutting-edge smart home technology.
Now you can use a pre-programmed routine, but it's not the same. You can put your lights on when a motion sensor goes off, have motorized shades close at sunset, or get your air conditioner at exactly 7pm. 1
More importantly, they are not the kind of thing you can actually do with voice commands – you have to go into a companion tab and configure them, which means you know exactly what you want to turn on and off and when you it will happen And if you have to go into an app to use a voice assistant correctly, something in that process doesn't work properly.
As far as I can tell, there is no technical reason that all these systems do not allow this, and yet you just can't do it. And yes, natural language processing is incredibly complicated, but I don't think that's the problem: the smart assistants themselves say explicitly that the software doesn't allow it. For example, Siri provides an answer that lets you know that it can't schedule commands. That means someone at Apple was aware that a user might want to do this, and then specifically tagged in an answer that says you can't. The problem does not seem to be an understanding.
In addition, may have a timer such as this for part of a function: all three companies offer a sleep timer especially for listening to music, apparently for when you fall asleep. But the net result is that you can ask Alexa or Siri to play music or audio playback to a timer, and turn it off when that timer ends. It's great! I wish I could do it with my lights, my TV, my fan, my air conditioner, and any other gadgets that were connected to my smart home.
Sleep timers are also not new technology. Home appliances such as TVs and air conditioners have had them for decades, leading to some weird setup. For example, at home I have an AC device connected to a smart plug. Wi-Fi connected plug can turn power on or off anywhere in the world, but it's not smart enough to understand the idea of "running for two hours and then turning off." The IR remote that came with the device does just fine but guess I can find it.
None of this is the end of the world: I can remember most of the time to turn off my lights, or cope with occasional irritation to wake up to realize that the AC is still running and that my room is an ice box. But there is yet another example of how for all their intelligence, smart assistants can often often fall into the small ways of fitting into our lives.