Pasterka

Pasterka is a Midnight mass celebrated by Roman Catholics during Christmas between 24 and 25 December across Poland. A close translation of the name would be the "Shepherds' Mass" (literally: 'that which belongs to the shepherds' in Polish), in reference to the Biblical shepherds, who were visited by an angel and told of the birth of Christ. During the "Pasterka" Mass, Polish people sing traditional "kolędy", Christmas carols from the Roman "calendae") in the spirit of joy.
Celebrations.
Although "Pasterka" mass is closely associated with the specific time in Christian liturgy, it is not the actual hour of the night that predicates its meaning. According to Polish ordinance of the Eucharist, the "Pasterka" is defined only by the type of prayer and biblical texts used during Christmas celebrations. It can be held more than once on December 24, in more than one location by the parish priest; at the church and at a nearby chapel. Often, there are two (or even three) "Pasterkas" celebrated next to each other – earlier ones for the families with children, then at 9 and 10 p.m. for the youth, and a final one at 12:00 midnight, for the adults.
The participation in the Birth of Christ celebrations is obligatory for all practicing Catholics. They have the option of attending any one of the evening masses or even more than one. Priests may refer to all of them as "Pasterka", even though formally they are called "Wigilia" masses by the episcopate as opposed to the grand mass at midnight. The exact hour of the birth of Christ is not written in the canonical gospels, which allows for choosing the ideal time for ritual prayer on that occasion. On Christmas Eve (December 24) and on Christmas Day, the masses can be celebrated from three different liturgical texts, each suited to a specific sacrament of the Eucharist. In the early hours, the worshippers can attend the Advent "waiting" mass, which does not excuse them from participating in the "Nativity" mass for the Birth of Christ later on.
There are no masses in the late afternoon on December 24, which is the time for Wigilia, the traditional supper at family homes. The first evening mass of the Christmas Eve (after the Wigilia) is celebrated around 4 p.m. or later before 8 p.m. followed by the 10 p.m. mass and the one-hour-long grand Midnight Mass, which begins at 12. Music for the Midnight Mass begins as soon as the doors open at 11:00 p.m. The Blessing of the Crib can take place before, or after the homilies, when the priests open the "Szopka" nativity scenes set up by the main altar. Traditionally, the service concludes with an Apostolic Blessing. The next day masses are interchangeable according to scripture, allowing for flexibility in choosing the religious services by individual parishioners. The Christmas Day begins with the early morning mass followed by daytime masses.
Pasterka is a Catholic mass specific to the Birth of Christ celebrations in Poland. Participation in Pasterka is synonymous with Christmas. Many practicing Catholics visit the Church twice on that occasion and are encouraged by the priest to do so. 