Elaine Schmitz, author of Recipes & Recollections of My Greek-American Family, put greetings in her email to me which I asked what they meant. They are below and might be useful if you want to put in a little Italian or Greek into your story’s dialogue.
Buon giorno is Good morning, Buon pomariggio is Good day. Buona notte is Good night.
kalimera is Good morning and kalispera is Good day, kalinikhta is good night.