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 home gadgets. But frustratingly, you cannot use the two features together: setting your lights to arbitrarily turn off in 30 minutes is impossible with today’s most sophisticated, cutting-edge smart home technology.

Now, you could use a pre-programmed routine, but that’s not the same thing. You can set your lights to go on when a motion detector goes off, have your motorized shades close at sunset, or have your air conditioner turn on at exactly 12:53PM on Tuesdays, Wednesdays, and Fridays. But with all three smart home platforms, you need to set up those routines in advance — they’re not the sort of thing you can just attach to a timer.

More importantly, they’re not the sort of thing you can actually do with voice commands — you have to go into a companion app and configure them, which means knowing beforehand exactly what you want to turn on and off and when you want it to happen. And if you have to go into an app to use a voice assistant properly, something in that process isn’t working right.

As far as I can tell, there’s no technical reason that all of these systems don’t 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 issue: the smart assistants themselves explicitly say that the software doesn’t allow it. Siri, for example, gives a response letting you know that it can’t schedule commands. That means that someone at Apple was aware that a user might want to do this, and then specifically coded in a response to say that you can’t. The issue doesn’t seem to be one of comprehension.

Furthermore, you can set a timer like this for part of one function: all three companies offer a sleep timer specifically for listening to music, ostensibly for when you’re falling asleep. But the net result is that you can ask Alexa or Siri to play music or audio playback to a timer, and shut 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 every other gadget plugged into my smart home setup, too.

Sleep timers aren’t new technology, either. Home appliances like TVs and air conditioners have had them for decades, which leads to some weird setups. For example, at home, I have an AC unit hooked up to a smart plug. The Wi-Fi-connected plug can turn the AC on or off from anywhere in the world, but it’s not smart enough to understand the idea of “run for two hours and then turn off.” The IR remote that came with the unit does it just fine, though, assuming 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 deal with the occasional annoyance of waking up to realize that the AC is still running and that my room is an ice box. But it’s yet another example of how for all their intelligence, smart assistants still can often fall short in the small ways when it comes to actually fitting into our lives.