In Ezekiel 16:7, the breast signifies natural good.

(References: Arcana Coelestia 3301)

In Exodus 29:26, this signifies the divine spiritual in the heavens and its appropriation there. It also signifies the good of charity. (Arcana Coelestia 10087)

Like other descriptions of time in the Word, "a day" or a number of "days" describe a spiritual state rather than our natural concept of time. A spiritual "day" describes a state of mind or a state in our relationship with the Lord rather than a 12-hour or 24-hour span of natural time. "Day" describes a state in which we are turned toward the Lord, and are receiving light (which is truth) and heat (which is a desire for good) from the Lord.