Biblical Hebrew Cosmology/When does a day begin?

WOW..At 02:48:14 So all this time, I've been outside looking up at the sky thinking I'm seeing stars float by and its these balloon payloads?

Also, is the waters of those firmaments flipped?

At 23:47 What I see in this 1st chapter of Genesis the Creation happening, not our instructions of what a day and night is but this is why we have those that go by evening to evening or sunset to sunset. I'm guilty I use to do that but I know better now. I also see that God is Elohim which is plural not meaning the ONE and Eternal FAther but could mean the Powers of the ONE and Eternal Father....