I believe that it is true. The Three Days have been announced by many mystics, viz., Bl. Anna-Maria Taigi, Padre Pio, Elizabeth Canori-Mora, Rosa-Colomba Asdente, Palma d'Oria, in Italy; Father Nectou, in Belgium; St. Hildegard, in Germany; Pere Lamy, Marie Baourdi, Marie Martel, Marie-Julie Jahenny, in France. (This list is not exhaustive; many more mystics have announced the Three Days.)
The Church does not oblige us to believe in any particular prophecy as a matter of faith [de fide], but we are indeed obliged to believe that prophecies may be made even in our own times, for this is in the Gospel [Evangelium]: the Holy Ghost will speak to many in the Latter Days.
Moreover, when an identical prophecy has been made by widely separated people in time and space, when this particular prophecy was accompanied by other predictions which have already come to pass, and when the holiness of the mystics in question has been recognized by the Church, we would be foolish indeed not to believe that the prophecy must come to pass. Such is the case concerning the Three Days of Darkness. How else could we explain that an illiterate peasant woman of Brittany is describing the very thing that another mystic in, say, Germany or Italy is also describing?
