This would seem to be a great feature that I would immediately implement. My wife always goes to bed before I do, so Night-mode always gets flipped on; sometimes it might be days before it gets turned back off. 

Night mode and dialogue! 

It’s mainly the sub. Yes, the timer would be great so you don’t have to check why it sounds so crap and then realise its still on!

S2 app still doesn’t have this feature or able to turn it on and off by voice. Why Sonos!????

A schedule would be great!

Would have been great to had this in the much over the top hyped S2 app.  

My Samsung soundbar that my playbar replaced has night mode.  After the Soundbar is turned off and back on it reverts to normal sound mode.  That seems easier to accomplish than a schedule.  Sonos has a very easy to use interface and adding a schedule feature would certainly muddy things up for this type of function.  I find myself forgetting to turn night mode off and realize it a couple of days later when I notice the absence of normal base.

Well as you know, Sonos speakers do not have an option to power off.

Good point,

I’d think with the software capacity of of Sonos, they could base it off of when the input sound source turned off.  The samsung has an auto-off function a minute or so after the input source stops.  Pretty basic.  Sonos could easily accomplish this.  

Already done. The HomeTheater device/surround setup is switching into stand-by mode 13 minutes after the TV set has been turned off.

Just to note that for those that can install Python and create/use simple scripts, SoCo-CLI [1] makes this kind of thing very easy.

E.g., switch to night mode at a certain time, switch back overnight:

sonos wait_until 21:00 : Lounge night_mode on : wait_until 05:00 : Lounge night_mode off : loop

[1] https://github.com/avantrec/soco-cli/blob/master/README.md