How are 3 days/nights in grave prophecy reconclied if Jesus died on Good Fri & arose Sun?

Did Jesus die on "Good Friday"? If so, how is it that 3 days & 3 nights are reckoned between Fri - Sun? “For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth” (Matthew 12:40).