The legitimacy of the spring holy day season as Christian doctrine cannot be overlooked or discarded. Certainly, the observances of Christ’s memorial and the related days of the festival of unleavened bread are credibly within the practices and personal teachings of the apostles and Jesus.
If we define a day in the context of Scripture, we must be careful that our definition of a day doesn’t arbitrarily change, because in some cases traditional interpretations can reason an earlier time for sunset, which of course loosens the moorings of the day from the calendar date.
So let’s look into this a little more.
Biblically, the beginning of a day is at sunset when the sun goes past the horizon, and it is not a variable point of time that can be moved or assigned to a previous day on a calendar, and the reason is a sunset fixes the day between two dates, which means that any given sunset marks the ending and beginning of two consecutive dates on the calendar.
For example, the sunset beginning the Day of Atonement is dated on the calendar as the 9th/10th and the sunset ending the day is dated as the 10th/11th of the month, and so the Day of Atonement is observed from evening to evening on the 10th day of the month.
The Hebrew word transliterated as erev, is sometimes translated as “evening” or “at even” in the Authorized Version of the Bible, and it can mean “night,” as we find in Genesis 1:5: “And the evening [erev] and the morning were the first day.” In this expression the word erev carries the understanding of sunset along with the ensuing night, and thereby it encompasses the first of two distinct parts of the day. (Here it is implied to be the evening beginning a day.)
In a similar manner the word erev can also refer to the approaching sunset at the end of a day. We find an example of this used for those who were considered “unclean,” or physically or ritually contaminated by some means, and so they were “unclean until the even [erev]” (Lev. 15). (See also, Deut. 23:11.)
However, the word erev can also be translated as “dusk,” which marks the sunset shortly before nightfall—when the sun sets over the horizon at the beginning of a day. An example of this usage is used to describe the nature of the changing cloud that was over the tabernacle. This cloud would cover the tent of the testimony while they were camped during the day, but “at even [erev] there was upon the tabernacle as it were the appearance of fire, until the morning” (Num. 9:15).
In this example, the cloud gave the appearance of fire in the evening because the “cloud abode from even [erev] unto the morning,” and so erev can indeed refer to a sunset at the beginning of a day (Num. 9:21).
However, in some cases, it becomes a matter of interpretation to properly apply the word erev to the period of time assigned to the Passover sacrifice, and depending on how we understand the context, the word erev can imply that the Passover was at the beginning of the day or at the ending of the day on the 14th of Nissan.
We can see why this is an issue when we examine Deuteronomy 16:6, which states that: “at the place which the Lord thy God shall choose to place his name in, there thou shalt sacrifice the passover at even [erev], at the going down of the sun, at the season that thou camest forth out of Egypt.” [Author’s emphasis throughout.]
In this example, the term erev can be interpreted to mean the sunset at the beginning of a day, or the sunset ending the same day. This means that to resolve the issue of the time for the Passover sacrifice we need to see how the word erev can relate to the phrase “between the two evenings”—the time when the Passover lamb was sacrificed.
Now we note that erev is said to have a dual form found in the Hebrew phrase beyn ha’ arbayim, which can also be translated as “between the two sunsets” or “between the two darknesses.” And in some cases the word erev can be interchangeable—in the general sense—with beyn ha’ arbayim, implying that this period of time is associated with sunset, when the sun sets over the horizon.
An example that is commonly used to show that “between the two evenings” applies to the sunset—“at even”—is found in Exodus 30:7-8, which addresses the time when the high priest burned incense in the morning and lighted the lamps “at even” (beyn ha’ arbayim) in the tabernacle. And by the simple sense of the text this lighting of the lamps would have to be at sundown, because Aaron and his sons were to set it in order “from evening [erev] to the morning,” which is similar to the expression used to describe the changing nature of the cloud that covered the tent of the testimony (Ex. 27:21).
Consequently, the phrase beyn ha’ arbayim would not be applicable to the afternoon of the day, when tradition reckons the time for the Passover sacrifice.
What then would this mean for the Passover festival and Festival of Unleavened Bread?
The calendar demonstrates that the Passover festival and Festival of Unleavened Bread are distinct observances one from the other, as the Festival of Unleavened Bread is specifically stated to fall on the 15th of Nissan, which is a Sabbath/holy day, while the preceding Passover festival falls on the 14th of Nissan, which is not a Sabbath. Therefore, because Scripture specifically assigns the Festival of Unleavened Bread to the 15th of Nissan on the calendar the Passover sacrifice cannot fall within the scope of the holy day as affirmed in Leviticus (See also Num. 9:2-3).
In other words, the Passover sacrifice could not take place on the 15th of Nissan regardless of the starting point for the sunset that begins that day, because the traditional sunset in the afternoon that begins the Passover sacrifice would also represent the beginning of the holy day on the 15th of Nissan. This, of course, would assume that the beginning of a Sabbath can be extended into the afternoon of the previous day, when the sun begins to descend in the sky, and thereby expanding the duration of the Sabbath day beyond the expected date of the 15th Nissan.
This is biblically not possible.
Therefore the Passover sacrifice that is reckoned “between the two evenings” on the 14th of Nissan cannot fall after a sunset beginning the 15th of Nissan, regardless of when that sunset is said to begin. Also the Passover sacrifice cannot fall in the afternoon of the 14th of Nissan—based on a traditionally established afternoon sunset—because that sunset would mark two dates on the calendar (14th/15th), and the 15th certainly didn’t begin in the afternoon of the 14th, and the 14th day of Nissan certainly didn’t end in the afternoon of the day. (What happened over time was that Rabbinic interpretation moved the sunset beginning the day back to the afternoon of the previous day, expanding the period of time from the early afternoon until sunset.)
Summarily, then, the Passover sacrifice must occur “between the two evenings” on the 14th day and date of Nissan, prior to the beginning of a Sabbath day at sunset, because the extension of the Sabbath day into the previous day is not supported in Scripture.
Let’s look at it this way.
As the sunset marking the 14th/15th of Nissan is the beginning of a Sabbath day, it cannot then be selectively and independently dated to the 14th day of Nissan in the afternoon, because that would extend the beginning of the Sabbath beyond the date of the 15th of Nissan—noting that the length of a day is measured from sunset to sunset. Consequently, the Passover sacrifice would have to occur before the Sabbath began on the 15th of Nissan, regardless of when it is reckoned to start, so even if the beginning sunset of the 15th was reckoned to the afternoon of the 14th of Nissan, the Passover sacrifice would still have to fall outside the 15th of Nissan—prior to the beginning of the Sabbath.
Which leaves us with the evening beginning the 14th of Nissan.
Now as the Passover sacrifice is stated to occur between the two evenings on the 14th of Nissan, the sacrifice cannot take place during the daylight portion of the 14th because the remains of the sacrifice had to be consumed in a fire beginning at daybreak. And as the Passover sacrifice occurs in a designated space of time it had to occur before daybreak, and before the angel passed over, and before the meal was eaten at night, which again brings us to the sunset and nightfall beginning the 14th of Nissan (Ex. 12:6, 8, 10).
(By implication the expression “the Passover at even” could then be said to mean the evening ending the 13th day of the month, because the Passover sacrifice is reckoned to the beginning evening of the 14th of Nissan, as understood from the application of “between the two evenings.”)
Historically, then, the Passover was a separate observance wherein the Passover sacrifice was originally a nighttime slaughter near the doorway of the house, and the time for this sacrifice, “between the two evenings,” is an appointed time that falls within the calendar date of the 14th of Nissan. This is clearly stated as such in Leviticus 23:5, which reads “In the fourteenth day of the first month at even [beyn ha’ arbayim] is the Lord’s passover [sacrifice].” (Torah tradition combined these observances into one feast, which became cluttered with various distinctions over time.)
Consequently, because the sacrifice would have to take place before the beginning of the Festival of Unleavened Bread (holy day), and before daybreak preceding that festival, and before the time of the “passing over,” the lamb would have to have been slain “between the two evenings” before it was eaten in “that night” of the 14th of Nissan.
This again brings us to the sunset and nightfall beginning the 14th of Nissan (Ex. 12:8). And this also brings us to the issue of the days of eating unleavened bread, which are concluded to begin “in the first month, on the fourteenth day of the month at even [erev].” 
(Continued in part-four of this series.)
