I am going to do my best and not get wrapped up in this debate this time on this forum. Having said that, the word "day" has a much broader definition than the most common usage of the word "day" to indicate a 24 hour period of time.
Here is Stong's definition:
H3117
יום
yôm
yome
From an unused root meaning to be hot; a day (as the warm hours), whether literally (from sunrise to sunset, or from one sunset to the next),
or figuratively (a space of time defined by an associated term), (often used adverbially): -
age, + always, + chronicles, continually (-ance), daily, ([birth-], each, to) day, (now a, two) days (agone), + elder, X end, + evening, + (for) ever (-lasting, -more), X full, life, as (so) long as (. . . live), (even) now, + old, + outlived, + perpetually, presently, + remaineth, X required, season, X since, space, then, (process of) time, + as at other times, + in trouble, weather, (as) when, (a, the, within a) while (that), X whole (+ age), (full) year (-ly), + younger.
Gen 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,
If, as many propose, the word "day" as it is used in
Gen. 1 must be and demands it is a 24 hour day, then there appears to be a problem and perhaps even an impossibility.
Look at this verse and notice what was called "days" in chapter one, is now called "generations" (indicating it is no doubt just referring to a span or a period of time), now here comes the problem. The totality of the creative "days" have not only now been called "generations" but all the "days/generations" (7 of them) are now referred to as "THE DAY" (singular)making it all to have happened in a single 24 hour period of time.
It is just an era.
Gen 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,
As far the evening and sunrise terms in chapter 1, merely refers to as one day/generation/era was fading away, a new day/generation/era was begining.