A school board in Ontario has discarded Halloween from the school calendar after some parents complained that their kids felt excluded, either because of a lack of costume or because their family did not celebrate the holiday. While I'm not personally a fan of the event, and would dread it every year as a kid until I was finally old enough that costumes weren't necessary anymore, I can't say I agree with this decision.
The reason is simple, some kids like dressing up. They like the costume, the face painting, the demands of candies from strangers in their neighborhood. These kids look forward to the day, and relish the opportunity to put on a costume of some kind and act like some kind of little demon or ghost. Some of these kids grow up into adults who love these same things, dressing up and going to various parties for the sake of good times.
It's simple reasoning then, it's not really right to deny some kids a day they enjoy just because of some other kids that are not going to celebrate the holiday. Then the question becomes what to do with the kids who don't want to partake in the festivities, or those who are unable to compete when it comes to costume construction. Let's focus on their needs for a moment.
The easiest solution comes with kids who cannot afford a costume, a school could sponsor a costume contest or a construction day. Materials are cheap, one can do a lot of stuff with inexpensive fabric, glue and a bit of cardboard, maybe throw in some paint for kicks. Giving all the kids in the class access to the same material levels the playing field, for more advanced students you have an opportunity to teach a bit about how to sew, and in general it's the kind of thing that encourages creativity. Even if such home made costumes lack the polish of store-bought creations, there's more pride in something you made yourself, and it's usually more interesting to have something unique for the day.
So what about the people who don't actually celebrate Halloween? For the most part, even though the holiday itself is so secular at this point that it's just a celebration of costumes and candy, there are people who object to it on religious grounds. It stands to reason, there is a lot of emphasis on the paranormal and death, and some people just don't want their kids exposed to these messages. The problem is, if we reject everything that doesn't conform to someone's beliefs, we reject everything, and these days which are supposed to be fun are replaced, and the change can't help but harm the kids who don't participate in the fun event other kids were looking forward to.
So instead, do the opposite. Engage these parents, find out what their family celebrates that should be part of the school holiday calendar. Look at events, festival, feasts and cultural touchstones and build a school day around those. Instead of trying to reject everything a student might find offensive, work with parents and kids to embrace special occasions a kid might enjoy. Rejecting things just because it's outside of someone's culture tends to lead to more resentment than inclusion, and it tends to build barriers within the community. Finding more excuses to celebrate does the opposite, and maybe the kids will learn about their classmates in the process.