Why did they say good morrow?
As part of a customary expression of good wishes on meeting or (less commonly) parting during the morning. Originally in “God give you (a) good morrow”; later chiefly in “to bid (also wish) (a person) a good morrow”, and (as an address) “a good morrow to you”.
Does Good morrow mean good day?
good morning
The morrow means the next day or tomorrow. We do depart for home on the morrow. Good morrow means the same as ‘good morning.