To each his own, folks. We choose not to celebrate Halloween, but I certainly have no problem with those who do.
Since both our church and our children's school also discourage it, I don't feel so guilty for them.
However, if I did celebrate, I would not feel the need to move it from Sunday to Saturday just because it is the Christian sabbath.
Although from a practical standpoint, I would feel guilty skipping evening services to get out during the daylight hours if they were younger.
Just be patient with people because quite a few do sincerely see it as a day "for the Devil". Although I am not quite that extreme, I can see the point.
As long as they aren't screaming that your kids are going to Hell or something equally offensive, just respect their beliefs.
(and save me some chocolate)