c.1300, "a period of the year," with reference to weather or work,
from O.Fr. seison (Mod.Fr. saison) "a sowing, planting,"
from L. sationem (nom. satio) "a sowing," from pp. stem of serere "to sow" (see sow).
Sense shifted in V.L. from "act of sowing" to "time of sowing."
In O.Fr. and O.Prov. this was extended to "season" in general (sowing season being the most important).
Seasonable is first recorded late 14c. Season ticket is attested from 1820.