but what we know as “Sunday” started at sundown on Saturday night, so there was plenty of hours he was in the tomb on the first day.
(One need MUST read the whole chapter of Matthew 12 to get the flavor of the instruction.) Matthew 12:40 For as Jonas was three days and three night in the whale's bell; so shall the Son of man be three days and three nights in the heart of the earth.
WHY was Christ so specific? He did not count a few hours here and there He said three days and three nights... HE knew when each 'new' day began. I contend He knew exactly what some would claim in the last 'days'.