Birthday, used as adj. P. and V. [face=SPIonic]gene/qlioj[/face]. Birthday offerings to the gods : P. and V. [face=SPIonic]gene/qlia, ta/[/face]. Hold birthday sacrifice : P. and V. [face=SPIonic]gene/qlia qu/ein[/face].
Seems that their birthday was a day for sacrifice. Now, what did greeks say in their friends' birthday to celebrate it? What was their equivalent to "Happy birthday!"?