Fix "Days Late" not incorporating years/months
Fix "Days Late" not incorporating years/months

Used the wrong format field (only incorporated $interval->d, not $interval->y or $interval->m).
RCOS-Grading-Server/HWserver,UuqV/HomeworkServerHack,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,UuqV/HomeworkServerHack,Submitty/Submitty,UuqV/HomeworkServerHack,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,UuqV/HomeworkServerHack,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,UuqV/HomeworkServerHack,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,UuqV/HomeworkServerHack