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Nuptial or Wedding Mass
A Nuptial Mass is highly recommended for a marriage when both parties are Catholic. It is allowed if at least one of the parties is Catholic. Since the non-Catholic party (unless Orthodox) may not receive Holy Communion, many pastors discourage a Nuptial Mass unless both may receive. In the special circumstances of pre-marital pregnancy, convalidation of vows after an annulment, while it is not explicitly forbidden it is inappropriate.
A wedding may be celebrated at any season of the year, although during the penitential seasons of Advent and Lent couples are asked by the Church to consider the special nature of these times and keep it simple. On Sundays of Advent, Lent and Easter, the liturgy of the Sunday with the wedding rites inserted is used. This is also the case whenever marriage is celebrated within a parish Mass on other Sundays. Otherwise, outside of Advent, Lent and Easter, either the Sunday liturgy or the Nuptial Mass may be chosen. Whenever the Nuptial Mass is used, white vestments are worn.
On the following days, however, weddings may not be performed within the Mass: Eastern Triduum (Holy Thursday to Easter Sunday), Christmas, Epiphany, Ascension, Pentecost, Corpus Christi, and any solemnity that is a holy day of obligation. In the US, this includes the Assumption, All Saints and the Immaculate Conception. Marriage may take place outside the Mass, however.