Unless you are on oblate of Le Barroux (or another monastery that retains this feast), today is not the feast of the Finding of Holy Cross.
But it should be.
The Finding of Holy Cross is one of those feasts that fell victim to the calendar reforms of the 1950s and early 1960s, when it was combined with the Feast of the Exaltation of Holy Cross (which celebrates the dedication of the Church of the Holy Sepulcre).
It celebrated St Helena's (mother of Constantine the Great) discovery of the Holy Sepulcre in Jerusalem, and subsequent discovery of the Cross at the site.
Here are the readings on the subject from the former Roman version of the feast:
After that famous victory which the Emperor Constantine gained over Maxentius, in the year 312, on the eve of which the banner of the Cross of the Lord had been given to him from heaven, Helen, the mother of Constantine, being warned in a dream, came to Jerusalem, in 326, to seek for the Cross. There it was her care to cause to be overthrown the marble statue of Venus, which had stood on Calvary for about one hundred and eighty years, and which had originally been put there to desecrate and destroy the memorial of the sufferings of the Lord Christ. The like work Helen did at Bethlehem, by cleansing from an image of Adonis the stable where the Saviour was born, and from an idol of Jupiter, the place where He had arisen from the dead.
Then she had thus cleansed the place where the Cross had stood, Helen caused deep excavations to be made, which resulted in the discovery of three crosses, and, apart from them, the writing which had been nailed on that of the Lord. But which of the crosses had been His was unknown, and was only manifested by a miracle. Macarius, Bishop of Jerusalem, after offering solemn prayers to God, touched with each of the three a woman who was afflicted with a grievous disease. The two first had no effect, but at the touch of the third she was immediately healed.
Helen, after she had found the life-giving Cross, built over the site of the Passion a Church of extraordinary splendour, wherein she deposited part of the Cross, shut up in a silver case. Another part which she gave to her son, Constantine, was laid up in the Church of the Holy Cross of Jerusalem, which he built at Rome on the site of the Sessorian Palace. She also gave to her son the nails with which the Most Holy Body of Jesus Christ had been pierced. Constantine established a law abolishing the punishment of crucifixion for all time coming and thenceforth what had hitherto been a hissing and a curse among men, began to be esteemed worshipful and glorious.