to arrive at (place or time) / period / to become due / classifier for events, meetings, elections, sporting fixtures, years (of graduation)
届
=
尸
+
由
:
Maud Younger (y) is being taught by a ghost (尸) how to mix a perfect Cuba Libre (由) in the elevator's bathroom (e4). She has to complete several sessions (届), and if she does, she will graduate this year (届).