Catechism of the Catholic Church §2743 — excerpt
It is always possible to pray: the time of the Christian is that of the risen Christ who is with us always, no matter what tempests may arise.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: St. John Chrysostom, Ecloga de oratione 2: PG 63, 585