This week according to the traditional calendar, Monday, Tuesday, and Wednesday are Rogation Days, on which we pray to fend off calamities and also for God's blessings upon the crops. These days have become known as the "Lesser Litanies" (as opposed to the Greater Litanies on April 25 which were established by St. Gregory the Great) and were established ca. 470 by St. Mamertus, Bishop of the French diocese of Vienne. During the reign of Pope Leo III (ca. 816), these rogations began to be observed in Rome.
At the beginning of the Litanies, an antiphon is sung. "Arise, O Lord, help us! Redeem us for your name's sake." Then the litany of the saints is begun.
Many traditional communities will be celebrating these litanies this week. Those without access to such a community might wish to chant the Litany of the Saints at home.