'Sabbath day' in the Bible

And as He was going thro' the corn-fields on the sabbath-day, his disciples began as they went along to pluck the ears of corn.

And the pharisees said to Him, See, why do they what is not lawful to be done on the sabbath-day?

and they watched Him, whether He would heal him on the sabbath-day, that they might accuse Him.