The General Roman Calendar indicates the days of the year to which are assigned the liturgical celebrations of saints that are to be observed wherever the Roman Rite is used. National and diocesan liturgical calendars, as well as those of religious orders and even of continents, add other saints or transfer the celebration of a particular saint from the date assigned in the General Calendar to another date. Canonization does not necessarily involve insertion of the saint's name into the General Roman Calendar, which mentions only a very limited selection of canonized saints.