Ebla

me-su /mīšu/ - night (VE 816, Kogan–Krebernik 2021b: 684)

PS
*mušy(-at)- - evening (CDG 368; Fronzaroli 1965a: 141, 147, 150; Kogan 2011: 196; Kogan 2015: 33)
Cf. PS *ˀamš-ay- ‘yesterday’.