Genesis 1:5: "And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day."
That's two different meanings of "Yom" in one verse. God called the light "day," as differentiated from night. And the period of light in a 24-hour day is less than 24 hours.
Genesis 2:4: "These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens."
Only heaven was created on the second day and earth on the third. Therefore "day" (and yes, it's the same Hebrew word, "Yom") means at least two separate days here.
“Day” doesn’t mean “epoch.” It means “day.”
Believe otherwise if you like. You seem to intent on believing this. Why? Why not just accept the word of God for what it says? This is not a complex passage.