Mark 15:42-47 comments: buried in a rich man's tomb

42 ¶  And now when the even was come, because it was the preparation, that is, the day before the sabbath,

Here is why everyone says that Christ was crucified on Friday because the Sabbath would have been Saturday even though it is said in different places that he spent three days and three nights in the heart of the earth.

Matthew 12:40  For as Jonas was three days and three nights in the whale’s belly; so shall the Son of man be three days and three nights in the heart of the earth.

But, this isn’t a regular Sabbath but a special Sabbath. This was a special high Sabbath.

John 19:31  The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the sabbath day, (for that sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away.

Read Leviticus 23 carefully.

There was 12 hours in a day and 12 hours in a night (John 11:9). The 24 hour day began with the evening before which is why creation in Genesis 1 is described as the evening and the morning of a day. Jesus spent three days and nights in the grave and at some point on Saturday night after 6pm but before 6am Sunday He arose. Jesus is killed on the Passover and the next day is a Sabbath and so is the next Wednesday in addition to the regular Sabbath.

43  Joseph of Arimathaea, an honourable counsellor, which also waited for the kingdom of God, came, and went in boldly unto Pilate, and craved the body of Jesus. 44  And Pilate marvelled if he were already dead: and calling unto him the centurion, he asked him whether he had been any while dead.

It was very common for a person to stay on a cross for a long time before they died but usually not ripped to shreds like Jesus was. People under crucifixion often stayed up there and slowly died.  It was a brutal death.

45  And when he knew it of the centurion, he gave the body to Joseph.

Here, he gives permission.

46  And he bought fine linen, and took him down, and wrapped him in the linen, and laid him in a sepulchre which was hewn out of a rock, and rolled a stone unto the door of the sepulchre.

Isaiah  53:9  And he made his grave with the wicked, and with the rich in his death; because he had done no violence, neither was any deceit in his mouth.

47  And Mary Magdalene and Mary the mother of Joses beheld where he was laid.

Luke 8 tells us that Mary Magdalene had seven devils removed from her. The Bible does not say she was a prostitute, which is another Pagan/Christian myth.