Have you ever wondered why we talk about Jesus spending three days in the tomb when we actually believe that he died Friday evening and rose again on Sunday morning?
Here is a great explanation by Ken Collins that I think is worth a look
The ancients counted days instead of calculating elapsed time—in fact, Jesus Himself counted days this way in Luke 13:31-32. This is why the tradition is universal that Jesus spent three days in the tomb when He was buried on Friday and rose from the dead on Sunday. All intervals in the Jewish and Christian calendars are calculated the same way, which is why Pentecost falls on a Sunday and not on a Monday. Read the entire article