It is customary to write in כתובות “on such and such day on such and such חודש.” But in גיטין, it is customary to write “on such and such day on such and such ירח.” The סימנים are כי יקח אשה חדשה, which appears in פרשת כי תצא in כד,ה. And גרש ירחים, which appears in פרשת וזאת הברכה in לג, יד.
06/10/2021