Automatic Update for X1 Box -- Manual Update of X1 Box

1. Recently I reset the Automatic Update feature from the default time to during the afternoon. I find the television screen works more consistently when I disengage the XI box for the night. Otherwise, I often get a black screen or one that struggles to remain stable, only to show a black screen the next day. So I'd like to know if the Automatic Update, which I've set for the daytime, will happen if I'm not in the room when the small window appears asking whether I want to update or not. In other words, will the update eventually happen if the window remains unaddressed? 

2. Is there any way I can update the X1 box manually and have full control and not leave the procedure to chance?