S1 Yom 7 - Month 7

Preparation Day and the 7th day of the Biblical Hebrew month starts at:
sunset on the 22nd through sunset on the 23rd of the Gregorian month.

[The 1st Day of the Seventh Month on the Biblical Hebrew Calendar is Yom Teruah and is commanded to be a rest day.  Leviticus 23:24, Numbers 29:1]

Six workdays must be counted off to establish the 1st Sabbath of every month, so unlike any other month, the 1st Sabbath falls on the 8th of the Hebrew Calendar in the 7th Month instead of the usual 7th day of any other Hebrew month.

Exodus 23:12

For six days do your work, and on the seventh day keep the Sabbath; so that your ox and your donkey may have rest, together with the son of your servant and the man from a strange land living among you.