The origin of this festival is unknown for sure, but it has been known since the Middle Ages in Europe. The celebration takes place in the San Juan Bautista Parish on March 11, 12 and 13. It is believed that its origin is linked to the objective of repairing the excesses that were committed during the days of Carnival and, possibly, to Christianize this pagan festival. The number 40 also has a clear biblical and religious importance since it is the years that the Israelites walked through the desert, the days that Christ was praying and meditating in the desert, or the hours he was in the tomb before being resurrected.

The XL Hours of Saint Gregory festivity is a very ancient and popularly esteemed religious celebration that consists of the exposition of the Blessed Sacrament throughout the day until nightfall. However, unlike what still happens in many churches and towns that celebrate this festival on established days, in Sant Joan and Mutxamel it is held on fixed days, without any relation to the Carnival.

In Mutxamel it is celebrated from March 10 to 12 and in Sant Joan from 11 to 13 of the same month. An explanation would come, perhaps, to avoid the coincidence of this celebration with that of the Virgin of Loreto, on March 1, a holiday that was an obligation in both towns, a fact that would have motivated moving the XL Hours to a few immobile days in the calendar. The name of Saint Gregory seems to come from the fact that the feast of Saint Gregory the Great was celebrated on March 12, before it was moved to September 3.

Today, the three days consist of an exposition of the Body of Christ from morning to night in the 17th-century silver monstrance. At dusk, an ancient hymn of invocation to the Trinity known as ‘Trisagio’ is sung, often performed by a children’s choir. Furthermore, on the last day, as a culmination, a cloister procession and blessing takes place in which the Band of the La Paz de Sant Joan Musical Society participates. The importance of this festival lies in its antiquity, traditional rites and public attendance, which makes it one of the most significant religious celebrations of Sant Joan d’Alacant.