When my son called on mother's day, we were surprised. We hoped that he would also call on father's day. He didn't disappoint. In fact, he called twice. Once to chat and once to wish me a happy father's day. The first call was on Saturday, the second was on Sunday - Father's Day.
I think it was a sort of "Airplane" sort of thing. "Turn on the runway lights." "No, they'll expect that."
I actually expected a call and I got it. I should have been aware that my son didn't wish me a happy father's day. He did on the second call - on father's day. He was starting his day (Monday) and I was ending mine. With the recent influx of troops, he now does little else but run and watch movies. He's home soon.