'New moon' in the Bible

And David said to Jonathan, Behold, tomorrow is the new moon, and I should not fail to sit at table with the king. But let me go so that I may hide myself in the field until the third day at evening.

And Jonathan said to David, Tomorrow is the new moon. And you shall be missed, because your seat will be empty.

And David hid himself in the field. And when the new moon had come, the king sat down by the food to eat.

And Jonathan rose from the table in fierce anger, and did not eat food on the second day of the new moon. For he was grieved for David, because his father had put him to shame.