In the scriptural calendar, the conjunction does not begin the month. At the conjunction no moon is visible. Deuteronomy 16:1 in the Hebrew tells us to “watch narrowly for the month (new moon) of green ears [of grain]” (RSB note). How can you watch closely for a new moon that cannot be seen? Often two or even three days of a dark moon precede the appearance of the crescent. Which invisible moon do you declare is the “right new moon”? Yahweh makes finding the first day of the month simple – it falls on the night you first sight a thin lunar crescent. No calculations necessary.