I just thought I'd add a note to the last post.
As a person who was raised as a (mostly) non-denominational Christian, and is now in a liturgical Protestant tradition, the idea of observing saints' days is still somewhat new to me. But what helps me understand this tradition is remembering St. Paul's injunction to "imitate me, as I imitate Christ." In the recognized saints, the church is saying, "Look at these people because they did a good job imitating Christ."
The thing is, it's sometimes hard to answer the question "what would Jesus do?" for the simple reason that you don't happen to be a first-century Jewish male in your thirties, letting alone the fact that you aren't the Messiah! When we look at the saints, we are looking at a wide variety of people who have imitated Christ: priests, missionaries, businessmen, children, fathers, mothers, monks, nuns, even kings and queens! Some of them may be in circumstances a little bit more like your own, but if most of them aren't, having all of these extra examples gives you a better idea of what following and imitating Christ looks like.
Now, you still imitate Christ primarily; the saints can't replace him in any way, shape, or form. But they're like older brothers and sisters who've been living with your parents' rules longer than you have, and can show you the ropes. You can look at them, and be encouraged, because they have proven that it's possible to follow Christ in every era, in every country, in every situation, no matter your age, race or gender.
At least, that's what I get out of observing saints' days. :D
peace of Christ to you,