Yeah, it is as specific as this in Genesis, 1:5
Strong's H3117 in the following manner: day (2,008x), time (64x), chronicles (with H1697) (37x), daily (44x), ever (18x), year (14x), continually (10x), when (10x), as (10x), while (8x), full (8x), always (4x), whole (4x), alway (4x), miscellaneous (44x).
And again:
Day: yôwm, yome; from an unused root meaning to be hot; a day (as the warm hours), whether literal (from sunrise to sunset, or from one sunset to the next), or figurative (a space of time defined by an associated term), (often used adverb):—age, always, chronicals, continually(-ance), daily, ((birth-), each, to) day, (now a, two) days (agone), elder, × end, evening, (for) ever(-lasting, -more), × full, life, as (so) long as (… live), (even) now, old, outlived, perpetually, presently, remaineth, × required, season, × since, space, then, (process of) time, as at other times, in trouble, weather, (as) when, (a, the, within a) while (that), × whole ( age), (full) year(-ly), younger.
This word seems to mean a period of time, an age since 24 hour days did not yet exist.
When we get into the, 'Begats" we can assume they are 'earth days.'
Prior to that there was no sun to, as scripture speaks of the 4th day.
Genesis 1:16
God made two great lights—the greater light to govern the day and the lesser light to govern the night. He also made the stars. 17 God set them in the vault of the sky to give light on the earth, 18 to govern the day and the night, and to separate light from darkness. And God saw that it was good. 19 And there was evening, and there was morning—the fourth day.
We tend to think the entire universe still revolves around and takes it's clues from the earth. It does not.
This is just in our little section of the woods
Mercury
Day length = 58.67 Earth days (1408 hours)
Year length = 88 Earth days (0.2 Earth years
Venus
Day length = 243 Earth days (5832 hours)
Year length = About 225 Earth days (0.6 Earth years)
Mars
Day length = 1.04 Earth days (about 25 hours)
Year length = 687 Earth days (1.9 Earth years)
Jupiter
Day length = 0.42 Earth days (10 hours)
Year length = 4333 Earth days (11.9 Earth years)
Saturn
Day length = 0.46 Earth days (about 11 hours)
Year length = 10,756 Earth days (29.4 Earth years)
Uranus
Day length = 0.71 Earth days (about 17 hours)
Year length = 30,687 Earth days (about 84 Earth years)
Neptune
Day length = 0.67 Earth days (16 hours)
Year length = 60,190 Earth days (165 Earth years)
Pluto
Day length = about 6 Earth days (153 hours)
Year length = 90,520 Earth days (248 Earth years)
This is just in our little section of the woods