Midnight mass is the first liturgy ( the form of prayer) of Christmastide ( period immediately preceding and following 25th December, the Christmas Day) that’s celebrated on the night of Christmas Eve, traditionally beginning just before the midnight of 24th giving way to Christmas Day. This midnight mass is a jubilant celebration in the honour of the Nativity of Jesus ( as the birth of Jesus is described in the Biblical gospels of Luke and Mathew) and it includes the celebration of Holy Communion ( also known as Eucharist, it’s a Christian rite and as per the New Testament, it was instituted by Jesus during the last supper , giving his disciples bread and wine during a Passover meal. As per Jesus, bread represented his body and the wine new covenant in his blood.)
As I read it somewhere, midnight mass is a tradition of Roman Catholic Church, though many churches now hold midnight mass at an earlier hour. Since 2009, the Pope has celebrated this mass at 10 PM and therefore it’s now also known as Mass during the night since 2009.
Each festival of different religions has these traditions and folklores associated with it and this what makes these festivals so full of happiness and gaiety.
Although social distancing and and Covid protocols are still in force, churches are gearing up for midnight masses for the devotees to participate either physically or virtually, on line!