What takes place at four in the afternoon, the very first day Bernov arrives for work?

At four in the afternoon on the very first day Bernov reports for work, two elderly employees go up to the compositors' room. They proceed to the icon corner and set up an altar on a table. Employees begin to stream in and stand on their designated sides. Frank is asked to light the candles. The parish priest enters and is accompanied by a deacon and a sub-deacon. He begins the service for the Feast of St. Modestus, the patron saint of printing.