Ezekiel 1:1-2 (KJV)
1 Now it came to pass in the thirtieth year, in the fourth month, in the fifth day of the month, as I was among the captives by the river of Chebar, that the heavens were opened, and I saw visions of God. 2 In the fifth day of the month, which was the fifth year of king Jehoiachin's captivity,
Ezekiel 4:5-6 (KJV)
5 For I have laid upon thee the years of their iniquity, according to the number of the days, three hundred and ninety days: so shalt thou bear the iniquity of the house of Israel. 6 And when thou hast accomplished them, lie again on thy right side, and thou shalt bear the iniquity of the house of Judah forty days:
Ezekiel 8:1 (KJV)
1 And it came to pass in the sixth year, in the sixth month, in the fifth day of the month, as I sat in mine house, and the elders of Judah sat before me, that the hand of the Lord GOD fell there upon me
It seems Ezekiel began his ordeal of lying on his right & left side seven days after the fifth day of the fourth month of the fifth year & ended on the fifth day of the sixth month of the sixth year.
In the sixth year he is found sitting before the elders of Judah. He could not have completed the 430 days.