'First Day' in the Bible

And it came to pass in the eleventh year, in the first day of the month, that the word of the LORD came to me, saying,

And it came to pass in the seven and twentieth year, in the first month, in the first day of the month, the word of the LORD came to me, saying,

And it came to pass in the eleventh year, in the third month, in the first day of the month, that the word of the LORD came to me, saying,

And it came to pass in the twelfth year, in the twelfth month, in the first day of the month, that the word of the LORD came to me, saying,

Thus saith the Lord GOD; In the first month, in the first day of the month, thou shalt take a young bullock without blemish, and cleanse the sanctuary: