 Others, with more probability, point to the fact that before the ninth century in certain places, for example at Rome, it was customary on the greater feast days to recite two sets of Matins, the one of the feria or week-day, the other of the festival.Hence such days were known as "doubles".The Catholic Encyclopedia of 1907 shows the incremental crowding of the calendar with the following table based on the official revisions of the Roman Breviary in 1568, 1602, 1631 and 1882, and on the situation in 1907.