As a father and a son, I just wanted to say a couple of things:
To all the fathers out there happy father's day.
Being a dad is probably the most significant thing I have done in my life it can also be one of the most thankless jobs in the world. Mom's like to complain about how their job is thankless, but I hear my kids tell her dinner is good all the time. When was the last time someone told you, "Dad all this electricity sure is great, thanks."
Call your dad, if you can't then sit back and remember a small seemingly insignificant moment. Those are the moment that separate dads from fathers. Any jackass with a check book can bail you out of jail, a dad teaches you how to throw a curve ball or explains the balk and infield fly rule.
Weekend Dads: Stop beating yourselves up and do the best you can with the time the courts give you. My dad was an every other weekend visitation dad, and the time I spent with him was some of the most important in my life. Since, I didn't see him every day the times that I did were never taken for granted. In short, you still matter, don't forget it.
My dad just recently talked to me about this very topic. He told me that he felt like crap for the better part of 25 years because he couldn't hold it together with my mom, so he could really matter in my life. I couldn't believe this was really how he felt. That is a lot of guilt for one person to carry, for something that he could not completely control.
So today, drink a beer watch the ball game with your son and teach him, even if he doesnt remember it still matters. Teach your son how to throw a four seem fastball (hell, teach your daughter a splitter) or dance with your princess. Whatever you do, enjoy your day, pat yourself on the back and take stock of the things in your life that are really important.