Works for me; however I often say the time before the action, so something like: “Alexa, at 8pm turn on the living room lights”, but “Turn the heating off in 15 minutes” also works for me.
It then creates a timer to activate said device/group at the time requested.
However all my devices are using the native smart home stuff in Alexa and they are exposed to Alexa via home assistant (So dunno if HA is doing some magic sauce to expose the devices in a certain way that allows such voice commands), So your mileage may (and indeed appears to) vary.
Granted sometimes it mistakes my intentions and I need to repeat myself.
I’ve also been able to create routines via voice, I first discovered that when Alexa suggested to me it could create the automation for me after it perform a request.
e.g. As a routine writer, you could include a command within a routine to turn on lights at 6am. However, it would be fixed at 6am whenever the routine runs, with no flexibility since there's no concept of variables or voice input available to routines. A more sophisticated platform would offer more flexible commands, i.e. "turn on lights at {voice_input}".
I can say "Alexa, set my alarm tomorrow at 7 in the morning". I wish I could say "Alexa, open my curtains at 6:45 in the morning tomorroe" instead of having to go to my cellphone and use the clunky Alexa app.
It just seems like a wasted opportunity for a routine. I'm sure a lot more things would be available if Amazon let developers use more features.
We're not asking to construct a complex schedule via voice command, the app is sufficient for that. Sometimes you just want your curtains opened at 6:45 tomorrow because something is happening and you just thought of it. That's would actually be convenient.
The "funny" thing is Google Home could do this (Turn on/off device after 8 hours) but recently they've removed the option & the assistant refuses. I assume it's for liability purposes, but it feels stupid.
Will the Google Home tell you the device names it can see?
The interface with smart devices is good but clunky. While I can say "Alexa open my curtains" and I can go to the slow and bloated Alexa app to open the curtains at a certain hour, I cannot say "Alexa open my curtains tomorrow at 6:45am".
I would love an app that would allow better automation, like doing an action at a certain time and playing an alarm X minutes later. However, skills are voice-only and nearly useless.