Birthday Season

Did you know it's "birthday season?" Neither did I, not until I walked into Target yesterday to buy a birthday card for my father. Apparently, he was born in season, but I wasn't. This has me vaguely concerned.

I'm not sure how I'm supposed to prepare for birthday season. I'd hate to do something inappropriate or at odds with the spirit of the time. I suspect Target just wants me to buy lots of stuff at their store. Not the most expansive reason for the season, perhaps, but they did invent it so I guess it's their call.