I don't know what to tell you, it worked for me.I really did it, i repeat for 7 times,use your save,but Billy just doesn‘t approach me....
I loaded up my 0.43 save, 3rd one from the top, followed the walkthrough from step 894 and Billy approached me at school after I did the 2nd movie scene
are you sure you completed both movie scenes.
EDIT: Just tested again and Billy approached at school the next day (Monday) right after I did the second movie scene with Janice.