'Sabbath day' in the Bible

So they came to Capernaum, and as soon as the Sabbath Day came he went into the synagogue and began to teach.

"Look," said the Pharisees to him, "Why are they doing on the Sabbath Day what is against the law?"

Then he asked them. "Is it lawful to do good on the Sabbath Day, or to do harm? to save a life, or to destroy it?"