Today we will uncover the secrets to success using dates in SQL, secrets not at all difficult to understand, once you've seen them. In a way, they're like magic tricks. If you know how the tricks are done, they're not really magic, although they may still be delightful.
This article contains explanations, tips, and examples for several different database systems, but makes no attempt to be exhaustive. There's just not enough space or time. My intent is to give you the confidence to deal with your own date situations, by helping you understand how they all work.