'First Day' in the Bible

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

Speak to the sons of Israel, saying, In the seventh month, on the first day of the month, shall be a solemn rest to 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.

However on the fifteenth day of the seventh month, when ye have gathered in the fruits of the land, ye shall keep the feast of LORD 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 to 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 LORD your God seven days.