在PSQL中为每个月创建存储“集合”？

I want to make a trigger or some kind of event over PSQL database that will trigger on end of the month and store data from one table (constrains data for each employee, when he came and went home from work each day) inside some kind of collection (database) of tables so I can still reach for that data if Im making monthly reports ( PSQL is the database, C# is used to make application). Any idea how to do that?I want to make a trigger or some kind of event