Harriet woke up in her dorm room and found a letter from the school's faculty, along with 12 small cards with some words written on them.
Congratulations on completing the coursework in the prestigious School of Cryptic Arts! Your training is almost complete. Written on these cards are instructions on when and where you can collect your diploma.
Of course, if you cannot manage to figure out the instructions in time, that means you have failed your training. In this case, you can pack your belongings and go home empty-handed. So you can consider this your final exam. Good luck!
How does Harriet figure out when and where she should show up?