'Sabbath day' in the Bible

Now Jesus came to Nazareth, where he had been brought up, and went into the synagogue on the Sabbath day, as was his custom. He stood up to read,

But the president of the synagogue, indignant because Jesus had healed on the Sabbath, said to the crowd, "There are six days on which work should be done! So come and be healed on those days, and not on the Sabbath day."

Then shouldn't this woman, a daughter of Abraham whom Satan bound for eighteen long years, be released from this imprisonment on the Sabbath day?"

Then he said to them, "Which of you, if you have a son or an ox that has fallen into a well on a Sabbath day, will not immediately pull him out?"