Visionary Conchita Gonzalez provides a profound insight into the alternate months for the Great Miracle at Garabandal. We should remember that this information was disclosed by The Holy Virgin to Conchita alone and no one else.
Source: 1981 Late Late Show from New York with host Gabriel Burns who interviewed the seer extensively about the apparitions.
The enormity of Garabandal is yet to be fully realized and is best demonstrated in a message to Albrecht Weber the author of 'Garabandal Der Zeigefinger Gottes' wherein Pope John Paul II thanking the author for promoting The Holy Virgins Messages wrote; " May God reward you for everything. Especially for the deep love with which you are making the events connected with Garabandal more widely known. May the Message of the Mother of God find an entrance into hearts before it is too late..."
Was Garabandal A True Marian Apparition? - vaticancatholic.com
Highly credible.
Interestingly, Garabandal is the only Marian Apparition to prove its authenticity by fulfillment of its own prophecies. The Church will then make its final declaration.