'Third Day' in the Bible

Turn back, and say to Hezekiah the prince of my people, Thus saith Jehovah, the God of David thy father, I have heard thy prayer, I have seen thy tears: behold, I will heal thee; on the third day thou shalt go up unto the house of Jehovah.

And Hezekiah said unto Isaiah, What shall be the sign that Jehovah will heal me, and that I shall go up unto the house of Jehovah the third day?