Wiktionary
n. 1 (context Christianity English) the hour of fasting and prayer before communion is to be taken. 2 (context Ireland informal English) the hour between 2.30 pm and 3.30 pm that pubs formerly had to shut to comply with licencing laws.
Wikipedia
Holy Hour is the Roman Catholic devotional tradition of spending an hour in Eucharistic adoration in the presence of the Blessed Sacrament. A plenary indulgence is granted for this practice. The practice is also observed in many Anglican churches.
Usage examples of "holy hour".
He did, however, follow it up with a report of what Prudence Vizard called her Holy Hour, which came every day at Angelus and was drawing larger and larger groups.
Without a word he continued to climb in the darkness and rain, determined not to profane this holy hour with idle words.
By sundown we will either be with the holy hour of Salat el Maghreb or in the arms of Allah.
The holy hour of nine-thirty was the part of his day that made life worth living.
She resolved that his hands would never stray up there except at the holy hour of the renewal of his disguise.