The more correct name for Halloween would be All Hallows Eve, that is the day ( or more specifically the night ) before the feast of All Hallows, that is All Saints. As the days grew shorter and the weather less clement (!) the Christian Community would gather to give thanks for all those who bore the Light of Christ is an darkened world – all the Saints. Because the feast of All Saints was such a day of rejoicing and a day of such Goodness, it was thought that the evening before the Feast (All Saints/All Hallows Eve) the powers which were less wholesome and Godly would try to cause as much chaos and disruption as possible – hence the ghoulish costumes, spiders webs and odd looking and smelling foods and drinks.
Thursday – the Feast of All Saints - is a day when we are called to gather together for Mass; it is a Holy Day of Obligation. You will see that we have Masses on Wednesday evening (Willaston) and also Thursday lunchtime (Douglas) and evening (Onchan) so that as many people as possible are given the opportunity to gather together for our HolyDay celebrations.
(If you are having a gathering for the family, and especially the children, on Wednesday evening, why not be a bit different and get them to dress up as a favourite Saint as opposed to a witch, warlock or devil??!!)