''Kalo Mina'' is the old traditional way of wishing everyone you come into contact with a 'good month'. You won't hear it as much in the big fast cities but on the Greek islands, especially with the older locals it is still a beautiful, looked forward to and welcomed custom. I'll tell you from personal experience, it is charming and uplifting, to have everyone you meet that first day of the month wishing you a good one. We can all use as much positive uplifting thoughts as we can get right?
Others we'll talk about are kali xronia, kali dromo, and kalo taxithi.
At the start of each new year or someones' birthday, the phrase you will say, and that you will hear thousands of times, is Kali Xronia (Kronyia). This is wishing them a good new year. Of course, usually accompanied with kisses on both cheeks.
To keep going along with all the 'goods' (Kali, Kalo, and Kala), When someone leaves your house lets say and they are walking or driving a bit you can say 'kali dromo', which is wishing them a good 'road'. Or in other words be safe on your little journey. If you are at the port and kissing your loved ones goodbye as they are entering the ship. You will say Kalo taxithi which is wishing them a good trip.
All these phrases make for a polite and traditional culture at least in the smaller authentic islands. So Kali tixi (teehee) on your next trip, hopefully to Greece.