Does The Sabbath Start At Twilight? (Part One)

Twilight is observable without technological aid, and perhaps this is one reason why the tradition endures of treating twilight, when evening begins and night approaches, as the start of the Sabbath.  Mere traditions, of course, are at worst invalid and at best optional but without any inherent significance, so tradition holds no philosophical weight.  If an idea is true, it is not true because people have believed or practiced it for generations; if it is false or non-obligatory, a mere social construct, it would be irrational for anyone to think otherwise.  As for the Biblical Sabbath, is there anything in the Bible actually in favor of what is otherwise an asinine tradition inherited by one generation of irrationalists after another?

First, I will provide the general Biblical information on this day of rest.  Of course, as with anything that does not pertain to literal genitalia, the Sabbath is for men and women, and it is also for the native-born and foreigners, for servants and the free, and for even animals to be refreshed (Exodus 20:8-11, 23:12, 34:21, Deuteronomy 5:12-15).  Sabbath violation absolutely does not have parameters as strict as some people might assume, for Numbers 28:9-10, Jeremiah 17:19-27, Matthew 12:1-13, and Mark 3:1-5 clarify that conducting priestly sacrifices, merely walking around, and healing other people are not prohibited work.  Even so, Exodus 31:12-17, 35:1-3, and Numbers 15:32-36 teach that the person who breaks the Sabbath deserves execution.  None of this is revoked in the New Testament as so many assume (Matthew 5:17-19, Mark 7:1-13, and so on).

Holding the Sabbath properly, therefore, is a fairly significant moral issue (though any moral issue is significant in itself), hence why the timing would be no small thing.  Some people point to Exodus 12 as confirmation that the day starts precisely at twilight/sunset according to the Bible.  However, what does the text say?  Exodus 12:6 says to slaughter the animals to be eaten for Passover at twilight.  The subsequent meal was initially to anticipate and then to commemorate (in later years) the death of the Egyptian firstborn and the deliverance of the Israelites from Egypt, which Yahweh would bring about that first Passover night (Exodus 12:7-13, 29-31, 42).  This is the reason why twilight is an integral part of both the narrative and the prescriptions for how to prepare for and partake of the meal.

This passage is about Passover in particular, not about recurring Sabbaths.  If there is a verse that directly addresses the Sabbath allegedly starting at twilight, it would not be found in Exodus 12, the reference to twilight concerning something else altogether.  Along with there being no direct affirmation that each day, according to the Bible, starts when the sun begins to set, there is nothing here to indirectly necessitate that the Sabbath must be kept starting specifically at twilight.  An annual Passover is not the Sabbath one is to have from week to week, only increasing the distinctions between them.  This chapter of the Torah is irrelevant to the subject of the Sabbath except for the parallels in how work other than that of making food is condemned on the first and seventh days of eating unleavened bread, which is connected to Passover (Exodus 12:16).