'New moon' in the Bible

And David said to 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 to the third day at evening.

Then Jonathan said to David, 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 had come, the king sat down to eat food.