I use clock widgets. The problem is that when I lock the phone, all applications are killed (except some system applications) including clock widgets. When I unlock my phone then I see that clock widget is stuck on time when I locked phone. I have to restart widget. Please tell me that how can I keep my clock widgets work in background without being killed when the phone is locked.
My problem is solved. Following link helped me.
I opened Phone Manager, then Power saving, then Protected apps and then I turned on the apps which I do not want to close after turning off my screen.