70. The Easter Vigil is celebrated by the whole Church, in the rites given in the relevant liturgical books. "The vigil of this night," as St. Augustine said, "is of such importance that it could claim exclusively for itself the name 'vigil,' common though this is to all the others."  "We keep vigil on that night when the Lord rose again and inaugurated for us in his humanity that life ... in which there is neither death nor sleep.... Hence, the one whose resurrection we celebrate by keeping watch a little longer will see to it that we reign with him by living a life without end." 
71. As with the Easter Vigil, it was customary to begin certain solemnities (different in different Churches) with a vigil. Among these solemnities Christmas and Pentecost are preeminent. This custom should be maintained and fostered, according to the particular usage of each Church. Whenever it seems good to add a
vigil for other solemnities or pilgrimages, the general norms for celebrations of the word should be followed.
72. The Fathers and spiritual writers have frequently encouraged Christians, especially those who lead the contemplative life, to pray during the night. Such prayer expresses and awakens our expectation of the Lord's Second Coming: "At midnight the cry went up: 'See, the bridegroom is coming, go out to meet him... (Mt 25:6). "Keep watch, then, for you do not know when the master of the house is coming, whether late or at midnight or at cockcrow or in the morning, so that if he comes unexpectedly he may not find you sleeping" (Mk 13:35-36). All who maintain the character of the office of readings as a night office, therefore, are to be commended.
73. Further, since in the Roman Rite the office of readings is always of a uniform brevity, especially for the sake of those engaged in apostolic work, those who desire, in accordance with tradition, to extend the celebration of the vigils of Sundays, solemnities, and feasts should do so as follows.
First, the office of readings is to be celebrated as in The Liturgy of the Hours up to the end of the readings. After the two readings and before the Te Deum canticles should be added from the special appendix of The Liturgy of the Hours. Then the gospel should be read; a homily on the gospel may be added. After this the Te Deum is sung and the prayer said.
On solemnities and feasts the gospel is to be taken from the Lectionary for Mass; on Sundays, from the series on the paschal mystery in the appendix of The Liturgy of the Hours.