Jn 19:31 The Jews, therefore, since it was the preparation day, in order that the bodies might not remain upon the cross on the Sabbath (for that Sabbath was a solemn day), besought Pilate that their legs might be broken...
Mark 15:42 Immediately after the account of Jesus' death: "Now when it was evening, as it was the Day of Preparation, that is, the eve of the Sabbath, there came Joseph of Arimathea..." to bury Jesus.
Luke 23:55 After seeing Jesus buried, the women "went back and prepared spices and ointments. And on the sabbath day they rested, in accordance with the commandment. But on the first day..."
So unless it took them a half-week to make ointments, this was on Friday afternoon, and the Sabbath prevented them from going back to annoint the body. Jesus would have been buried around 3 pm, not six, since six would probably have been getting too close to dark, which is when the Jewish Sabbath begins.
I don't have my Bibile with me just now, but one of the Gospels refers to this Sabbath as a "high day Sabbath" meaning it is a special feast day, not just a Saturday.