let me see if I understand the question....
There are 2 schools of thought on this; one takes the day before the Sabbath to be a Friday , counting that as one day (since the Lord was in the ground before it). then all day Saturday; until sunrise of the First day... approximately a 40 hour period...and counting that as three days.
The other school of thought is that Christ was crucified on the Fourth Day... the day before Passover; with the understanding that any Holy day... such as Passover is considered a Sabbath... there by being in the Ground Wednesday, Thursday, and Friday nights... and Thursday Friday and Saturday in the Day... 3 complete days and 3 complete nights. There is no mention as to exactly when the Lord rose before the First day, just that at dawn the Tomb was empty...
Now as I had mentioned when I first joined I am no scholar teacher or preacher...so take my opinion for what it is worth...
This is wonderful brain fodder. It is Totally irrelevant as well. It falls into the category of useless argument and senseless debate to totally distract and misdirect from the Blessed Truth that the Lord Died, was Buried and Rose Again. So while this may be an excellent tidbit tor intellectuals to scratch their brain over... it is not an issue to get all caught up in. Whether these occurrences happened over a 40 hour span or a 72 hour span has no bearing our Salvation or on the Truth that Jesus Lives!