Both parents play the main roles in their children's lives
AS with Mothers Day, Fathers Day is a specific day to celebrate and honour love; in this case, love for a father, whether biological or otherwise. And, as with Mothers Day, for happy families, Fathers Day is merely a formality; special because it is observed, but relevant only if father is loved. Indeed, many families may not go to great lengths to celebrate today, or even formally recognise it. And for happy fathers with happy families, this is all right.
Fathers who are loved are honoured and celebrated every day, in small and big ways. These fathers get hugs and kisses, smiles and gurgles, requests to help with homework, the tying of shoelaces, the fixing of a squeaky cupboard door and introductions to their children's friends and acquaintances as "my father/daddy/papa". In their children's adulthood, fathers who are loved are honoured with one of the precious two or three tickets each graduand is given for entrance into the convocation hall, and are permitted to play a big role on their child's wedding day; those things that may seem like a done deal the moment a person becomes a parent, but are actually up to the discretion of the child.
For, in truth, the men who are honoured and celebrated on Fathers Day are the men who are fathers every day. They are there to see the smiles because they are around to see the tears as well; they are there to watch their children win prizes at school because they were there to help supervise the children's studies; they know what their children like to eat because they prepare meals for them and sit down to meals together. They are able to protect their children because they bathe and clothe them when young, talk about the day's happenings and discuss joys and worries, and, thus, cannot be ignorant of any changes to the child. And they are there not only to watch, but to be watched. They also set examples of what it means to be a man, a son, a brother, a father, a spouse, a human being and a member of society.
As with being a mother, being a father is hardly easy. In fact, with modern life and modern costs requiring families to be dual-income, this means that fathers, like mothers, must bear the burden of earning money as well as taking care of the home and the children. Having to do all this alone, as single parents well know, is a stressful juggling act that is impossible to complete successfully without support. In a functional dual-parent family, even though both parents are supportive of each other, neither plays just a supporting role. And that's what it means to be a good parent.