While the word "Halloween" is a label for a pagan holiday, the word is actually derived from a Catholic holiday that coincides with the date. "All Hallows Eve" and "All Souls Day" start at sunset on 10/31.
It's like wishing people "happy holidays" at the end of each year. Halloween has lost it's original pagan meaning and is just a fun time for kids (and adults) to dress up and goof around a bit. Nobody really cares about it's origin any more.
