"On the next day, which followed the Day of Preparation, the chief priests and Pharisees gathered together to Pilate" (Matt. 27:62). Although the wording here is subject to interpretation, it seems most likely that the Jewish authorities gathered to Pilate at the start of the Sabbath (i.e., early Friday evening--by our way of reckoning time--shortly after Jesus was placed in the tomb). It seems doubtful that they would leave Jesus' body unguarded for one night since the disciples would have been just as likely to steal it the first night as the second.
They spoke to Pilate in Matthew 27:63 - "Sir, we remember, while He was still alive, how that deceiver said, 'After three days I will rise'" (cf. 12:39,40; Mark 8:31). Even after His death, they, with malice in their hearts, continue to berate Him! Technically speaking, as we reckon time today, Jesus was in the grave for a maximum of one full day (Saturday), two full nights (Friday & Saturday), and a portion of two other days (Friday & Sunday). In our modern usage, there is no way to reconcile this fact with the statements recorded in Scripture: "three days and three nights" or "after three days." However, the problem is easily reconciled when one considers the way those in the first century (and before) wrote and spoke about time. People often counted any part of a day as the whole day and night. Let us briefly consider a few passages that illustrate this fact.
Esther 4:16 conveys that the queen would fast for a period of three days (she would not eat "night or day"), and then she would risk her life and go speak to the king. Today, we would understand her words to mean that she would fast three full days and then go speak to the king, but that is not what she meant. "On the third day" she approached the king (Est. 5:1). Similar comments can be made regarding Genesis 42:17,18 and I Kings 12:5,12. Additionally, Acts 10 is worthy of a close inspection. A careful reading will show that Cornelius prayed to God on "Day 1" and Peter arrived on "Day 4" (cf. 10:3,9,23,24). Then, Cornelius declared in Acts 10:30 - "Four days ago I was fasting until this hour; and at the ninth hour I prayed..." For the sake of illustration, let's pretend that "Day 1" was Sunday. Thus, "Day 4" would be Wednesday. However, when it is Wednesday, how many of us today refer to Sunday as "four days ago"? No one that I know today does this. To the modern way of considering time, Sunday is three days ago. Understanding this difference in reckoning time is the solution to understanding how Jesus could be buried for "three days and three nights" and yet not literally be buried for at least 72 hours.
Thus, the phrases "on the third day," "in three days," "after three days," and "three days and three nights" are all equivalent periods of time in Jewish usage (Matt. 16:21; 27:63,64; Luke 9:22). There is no contradiction regarding the duration Jesus was buried, and the attempts of some to "force" the view that Jesus was actually in the tomb for 72 hours (by suggesting that Jesus died on a Thursday) are incorrect and impossible to harmonize logically (especially since He was buried in the late afternoon prior to the Sabbath and arose in the early morning just after the Sabbath, cf. John 19:31; 20:1).