For Bloody Hell players who want to get the Sunday Bloody Sunday achievement, this guide will explain how to unlock it.
Way to get
It is only necessary to kill Satan and God (perhaps on an old save if you have already done it) on Sunday or so that Sunday is displayed in your operating system.
Therefore, there are two obvious ways of obtaining:
1) Wait for Sunday to come, enter the game, load a save (new or old) and finish the game.
2) It’s an old date manipulation trick on your PC: in the date settings, manually change the date to any Sunday and again “go into the game, load a save (new or old) and finish the game.”