8 “Remember the Sabbath day, to keep it holy. 9 Six days you shall labor, and do all your work, 10 but the seventh day is a Sabbath to the Lord your God. On it you shall not do any work, you, or your son, or your daughter, your male servant, or your female servant, or your livestock, or the sojourner who is within your gates. 11 For in six days the Lord made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy (Exod 20:8-11).
This is a classic prooftext for YEC/the calendar-day interpretation. However, I think there are nuances which interpreters usually miss.
i) The command was initially addressed to Israelites in the Sinai desert. (Of course, the command isn't confined to that setting.)
ii) Working for six days before taking a day off doesn't mean working 144 hours straight. Humans need to eat and sleep. So in this context, a "day" is shorthand for the daylight hours. People used to work outside from first light until dusk.
a) That's in part because they needed sunlight or daylight to see what they were doing–especially when working out of doors.
b) That's in part because it was more dangerous to be outside after dark. Nocturnal predators were on the prowl. Likewise, you could accidentally step on a venomous snake.
c) Not to mention how frighteningly easy it was to become lost in the dark. You could be a few hundred years from home, but be unable to find your way back in the pitch black darkness.
iii) A campfire could provide some illumination, although that's quite limited. Even in the age of electrical lighting, most folks don't work outside at night.
iv) Then there's the question of indoor lighting. Firelight can provide indoor lighting, but firelight generates smoke. So you need ventilation, especially in a small, one-room dwelling like a tent. I don't know if ancient tents had a smoke flap, like a teepee. But I'm sure they didn't have a fireplace with a chimney.
v) Another issue is the availability of firewood or lamp oil. I expect these were in short supply in the Sinai desert.
So my operating assumption is that the wilderness generation didn't work at night.
vi) What makes the Sabbath special, what make the Sabbath sacrificial, is that an Israelite is taking the whole day off. These are the most productive hours of the day. Not just when most of the work gets done, but the only time when most of the work can be done.
vii) The interval between dusk and dawn varies with the season and the latitude. Long winter nights, short summer nights. In extreme northern latitudes you can have weeks of continuous daylight in the summer along with weeks of continuous darkness in the winter. So the duration of a "day" is variable in that respect. Depends on where you live.
viii) Turning to the counterpart in Gen 1:1-2:3, I don't think this means God worked nonstop for six days. Creation is a daytime occupation. The daylight hours are the business hours. God punches the clock, closes shop after dark, then resumes the morning after.
ix) That, in part, explains the function of the evening/morning refrain. I think that's more accurately rendered dusk/dawn. It demarcates the interval between sundown and sunup. In other words, it denotes "night."
x) In addition, there was already divine "rest" between each working day. Nighttime marks the temporary cessation of God's creative activity. The reason the evening/morning refrain is conspicuously absent from the seventh day is not because that never ends, but because, on the seventh day, God takes a whole day off–in contrast to knocking off work after dark. Every night, God takes a break–but on the seventh day, the entire day is a day off.
ix) And that explains why the creation of light is the first divine fiat. A builder needs light to see by. Both Gen 1:1-2:3 & Exod 20:8-11 turn on the availability of sunlight to work outside.
x) This means Gen 1:1-2:3 is fairly anthropomorphic in that regard. As if God is subject to the limitations of a human being, who lacks nocturnal vision. So Gen 1:1-2:3 reflects divine accommodation.
xi) However, that's ambiguous. Divine accommodation can mean different things:
a) It can mean Scripture uses anthropomorphic depictions because it isn't literally possible for God be in that condition. For instance, Scripture attributes organs and body parts to God (eyes, ears, arms). Of course, God doesn't literally see and hear. But they symbolize omniscience. God doesn't literally have a mighty, outstretched arm. But they symbolize omnipotence.
Even in this case, we're dealing with analogies.
b) Or it can mean God actually behaves as if he's limited. There's nothing that prevents God from producing things in the daytime, but refraining from creative action at night. So that could be literal. Or it could be anthropomorphic.
It's not only, necessarily, or even primarily, about the timeframe or the temporal sequence, but about working conditions–which require sunlight. Not just about chronometry, but natural illumination. Not so much about the measurement of time or timekeeping, but about a precondition for labor: visibility. I think interpreters tend to overlook that because they fail to project themselves into that primitive environment.