No, because the STB does not have that function.
That would be something for your TV.
FIOS remote only supports rudimentary TV functions.
There is an "Auto Off" feature that can be a work around for you. Press the MENU button, Settings, System, Media Client Settings, Auto Power Off, then choose None, 1, 2, or 4 Hours.
You need top know this setting will remain active until you go into the Settings to change it. It's kind of like the sleep setting on your computer - the timer starts over every time you issue a command through your remote (change channel, change volume, pause, ect), so if you set it for 1 hour, and 55 minutes after you've been watching it, you lower the volume, the internal clock resets and it will be 60 minutes before it shuts off. On the other hand, if you're laying in bed watching a two hour movie and don't touch the remote at all, and have the 1 hour setting, the cable box will automatically shut off.
That only shuts down the STB.
TV will still remain on.
So depends on what the OP was looking for.