Here is a small section from a synopsis I’m working on that explains the so called discrepancies. I underlined the portion concerning the sixth and third hour.
McEvilly Matthew says, “And they gave Him wine” &c. In some Greek copies, for wine we read vinegar. However, St. Jerome and St. Hilary read, wine, as in our Vulgate. St. Mark (xv. 23), has, “wine mixed with myrrh.” The most probable mode of reconciling this discrepancy is, that the Greek word for vinegar, sometimes denotes a poor sort of wine, and the Greek word for “gall” sometimes means, a bitter drug. It is used by the LXX. to signify, absinthium, so that it denotes the same thing with the myrrh, referred to by St. Mark. It may be, that both ingredients, “myrrh” and “gall,” were added, to render it more bitter. It was customary, before crucifixion, to give persons, about to be executed, a potion, out of pity and humanity, in order to give them some consolation and refreshment, and also to strengthen them to bear their torments with greater fortitude. But, such was the malice of the Jews, that this potion was converted into a nauseous, bitter draught, not to be endured. The drink here given is different from that referred to (v. 48), and by St. Luke (xxiii. 36), St. John (xix. 29). In the former are verified the words of the Psalmist, “dederunt in escam meam fel;” in the latter, “et in siti mea potaverunt me aceto.” The former was given before His crucifixion, and it; was wine; the latter, in the crucifixion, and it was vinegar…. The day of our Redeemer’s crucifixion was the 25th of March ; the hour, about mid-day. St. John says, it was “the sixth hour " (xix. 14), from sunrise, which was mid-day. “It was the third hour,” according to St. Mark (xv. 25). But, he means “the third hour," now closing, which was the commencement of the sixth hour. For, each hour in the computation of their four watches contained three hours among the Jews and Romans. Tertullian (Lib. contra Marcion), and others, say, that our Lord was crucified on the same day, in the vernal equinox, on which Adam was created, and was crucified at the same hour, at which he ate the forbidden fruit… The four Evangelists describe the division of the garments, the inscription of the title, and the crucifixion of the two robbers, not in the same order. St. Mark (xv. 24, &c.), follows the same order of narrative with St. Matthew. St. Luke (xxiii. 33, &c.), describes the crucifixion of the robbers first; then, the division of the garments, and finally, the inscription of the title. St. John, whose order of narrative is deemed the most accurate, as he wrote after the others (xix. 18, &c.), places the crucifixion of the robbers first, the title next, and the division of the garments in the last place. The words of our Redeemer on the cross, described by St. Luke (xxiii. 34), “Father, forgive them” &c., should be inserted before these words, in the order of narrative. Then, “they divided His garments, casting lots." This is more circumstantially and more distinctly narrated by St. John. (xix. 23, &c.) He informs us, that the soldiers divided His garments into four parts, so that the soldiers, who were four in number, received a part, each. From the words of the soldiers, in reference to the seamless (inner) garment… Matthew says, “And they" that is, the soldiers, His executioners, by the command of Pilate (John xix. 19), “put over His head,” that is, on the portion of the cross, which was above His head, “His cause written.” that is, the alleged crime for which He was condemned to death. Mark (xv. 26) calls it, “the inscription of His cause;" Luke (xxiii. 38), “a superscription;” John (xix. 19), “a title.” They all mean the same thing, viz., the words written, or, rather, legibly cut on a board or tablet placed over His head, and indicating to all the charge on which He was condemned to death. It is not likely, that the words were inscribed on the arm of the cross, placed above His head, as it would hardly contain space enough to have the words inscribed in large, legible characters, in three languages. It is a very ancient Oriental custom to have these titles either attached to every malefactor condemned to death, or borne before him. This title of our Redeemer was written in three languages, which were consecrated on the cross of Christ; the Hebrew, the vernacular of the country; the Greek, then most extensively diffused; and the Latin, on account of the majesty of the Roman Empire. It is given differently by the four Evangelists, who agree, however, in substance. That given by St. John, “Jesus of Nazareth, King of the Jews,” is generally considered to be the most exact title, because St. John saw it at the crucifixion, and wrote after the other Evangelists; and also, this corresponds with the title, which, as a most precious relic, is preserved at Rome, in the Church of the Holy Cross. In this relic, the only word perfectly legible is “Nazarenus.” As the Hebrew form, like all Hebrew writings, was written from right to left; so, in the Greek and Latin inscriptions, the same order, contrary to the usual custom, was observed. The writing of the title in three languages, the language of the Jews, and the principal languages among the Gentiles.