'First Day' in the Bible

In the first day ye shall have a holy convocation: ye shall do no servile work.

Speak unto the children of Israel, saying, In the seventh month, on the first day of the month, shall be a solemn rest unto you, a memorial of blowing of trumpets, a holy convocation.

On the first day shall be a holy convocation: ye shall do no servile work.

Howbeit on the fifteenth day of the seventh month, when ye have gathered in the fruits of the land, ye shall keep the feast of Jehovah seven days: on the first day shall be a solemn rest, and on the eighth day shall be a solemn rest.

And ye shall take you on the first day the fruit of goodly trees, branches of palm-trees, and boughs of thick trees, and willows of the brook; and ye shall rejoice before Jehovah your God seven days.