Maybe I need to reword a bit.

I want to know what script is needed to make the advisor to annoce season/year at each of the turn.

Each time you end a turn, on next new beginning turn. You seen an alert from the advisor with a text box saying what is the current season/year.

Start of the game,

Spring, 280BC

End turn,

Summer, 280BC

End turn,

Fall, 280BC,

Etc...