Was Jesus really only in the grave for one whole day?

It is proposed that when Christ said he would spend three days in the earth that he must have meant Friday night, Saturday and the night, and the beginning of Sunday. But is this true? In Matthew 12:40 Christ said, "For as Jonas was three days and three NIGHTS in the whale's belly; so shall the Son of man be three days and three NIGHTS in the heart of the earth." This means all Thursday, all Friday and then all Saturday. Then to be risen already on Sunday morning. Confusion arises because the scriptures talk of the body needing to be quickly buried because of the coming sabbath. But was the coming sabbath spoken of the weekly sabbath (in the law of Moses there were several sabbaths, not just the weekly one). That year there was another sabbath due on Thursday. So was he was crucified on Wednesday and quickly buried to be "in the heart of the earth" for the three days and nights til Sunday morning (as prophesied)?