There are 4, each with its season:
(a) during Advent and until the Purification of the Virgin Mary, Alma redemptoris mater;
(b) from then until Wednesday in Holy Week, Ave regina coelorum;
(c) from then until Whitsun, Regina coeli laetare;
(d) from the Octave of Whitsun until Advent, Salve regina, mater misericordiae
.