How the Night Office Is to Be Said in Summer Time
Feb. 12—June 13—Oct. 13
From Easter until the Calends of November let the same number of Psalms
be kept as prescribed above; but no lessons are to be read from the
book, on account of the shortness of the nights. Instead of those three
lessons let one lesson from the Old Testament be said by heart and
followed by a short responsory. But all the rest should be done as has
been said, that is to say that never fewer than twelve Psalms should be
said at the Night Office, not counting Psalm 3 and Psalm 94.