Automatically power-on Android phone at a given time? Is it possible to automatically power on Android phone at a given time?
Technically, if your device is connected to a charger, it may be possible if your phone is rooted. 

You can edit the program which shows the charging animation when your phone is powered off (typically stored in playlpm or lpm in /system/bin). 

You could replace it with a simple shell script to reboot the phone when the time is equal to some value, assuming the system booted at that point has the date command available.   

Obviously, this isn't an end-user solution. It's only for people who know at least a little programming and know what they are doing. 

Source: https://arduandro.wordpress.com/2014/07/03/autobootstart-android-when-charger-is-connected/

Here is something to get you started. This should reboot your phone once it's 4pm (untested):

#!/system/bin/sh
while:
do
hr=`date +%H`
if test $hr -ge 16
    then
    /system/bin/reboot
else
    sleep 60
fi
done