'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 to David, To morrow is the new moon: and thou shalt 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 meat.