'New Moon' in the Bible

And David said unto Jonathan, Behold, to-morrow is the new moon, and I should not fail to sit with the king at meat: but let me go, that I may hide myself in the field unto the third day at even.

Then Jonathan said unto him, To-morrow is the new moon: and thou wilt be missed, because thy seat will be empty.

So David hid himself in the field: and when the new moon was come, the king sat him down to eat food.

And it came to pass on the morrow after the new moon, which was the second day , that David's place was empty: and Saul said unto Jonathan his son, Wherefore cometh not the son of Jesse to meat, neither yesterday, nor to-day?