Q: If our parish is having an evening, daily Mass on August 14, do we need to celebrate the Vigil for the Assumption of Mary (August 15) at that Mass, or can we celebrate the normal daily Mass which was for St. Maximilian Kolbe? In general, if a Mass is being celebrated after 4pm, does it have to be a Vigil Mass and when? Never, Only for all Holy Days of Obligation, for all Sunday Masses, all Solemnities, etc. I think the Missal permits it for all Solemnities, but I don’t think it is required. Thank you in advance.
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A: As best as I can tell, you are not obliged to celebrate the Vigil on August 14, especially if you have a regularly scheduled evening daily parish Mass. The same applies to any Saturday—you could celebrate a Saturday evening Mass that is the liturgy of that Saturday.
However, if people are using that Mass to fulfill their canonical obligation to participate, then you’re not doing them a favor. Using the readings and prayers of the obligatory day would be to their pastoral and spiritual advantage.